HIS HD6990 4GB Graphics Card Review

Part two of our dual GPU round-up and we take a closer look at HIS’s dual GPU equivalent to Nvidia’s GTX590, the HD6990.

Product on Review: HIS Radeon HD6990 4096MB
Manufacturer and Sponsor: HIS
MSRP: US$699
Street Price: £460-£550

AMD are no stranger to dual GPU single graphics card. Some could say they even pioneered the idea prior to the concept becoming more ‘mainstream’ after Nvidia’s attempt. Some might remember ATI’s Rage Fury Maxx which held two Rage 128 Pro chips. Although CrossFire did not exist back then, they worked in an Alternate Frame Rendering configuration, similar to modern day implementation of SLI and CrossFire. The concept was not successful due to the lack of dual GPU support on Windows and AGP, but recent times has shown the efficiency that could be achieved under new Windows environment and thanks to new PCIe standards. It was in the RV670 era that AMD decided to adopt the dual GPU idea. After failing to create a card that could compete with Nvidia’s offering at the high end, they decided to package two of their more mainstream offerings onto a single card to attain performance enthusiasts sought. The idea was soon adopted and paved AMD’s future line up of cards. Their road maps revealed that they would focus on smaller, highly efficient GPUs that would target the £300 price point and lower, and to please the niche enthusiast market, they would simply have one card holding two such GPUs via CrossFire. It was a promising concept and one that has transferred well into the market. The HD4870x2 and HD5970 proved highly successful and easily outperformed Nvidia’s monolithic designs at similar price points. Today we will look at AMD’s successor to the HD5970. Codenamed Antilles, the HD6990 packs two Cayman based HD6970 GPUs on one card and if recent improvement in CrossFire scaling are anything to go by, the HD6990 will challenge Nvidia’s GTX590 very closely indeed.

Both Nvidia and AMD have settled on very similar design cues for their dual GPU cards. Both have taken their most powerful GPU, GF110 and Cayman respectively, and placed them onto a single PCB. To lower power draw given their GPUs’ incredible hunger for power, both companies have decided to lower the respective clock speeds but still making sure the architecture was not compromised. As such, the individual cores aboard the HD6990 still boast an impressive 1536 shader count, 96 stream processors, 32 ROPs and 256-bit memory bus. In doing so, the clock speed had to be reduced to 830MHz on the core and 5GHz on the memory to meet the already out of specification 375W TDP. It effectively means that the HD6990 is two HD6970 with slightly lowered clocked. Comparatively, the HD5970 suffered a greater clock speed deficit from its HD5870 derivative making the card more in line with CrossFire HD5850 performance. The HD6990 should hopefully be closer to HD6970 CrossFire performance than dual HD6950 performance. Furthermore, AMD have lowered the voltage at which the GPUs operate to ensure that the card fits within the 375W envelope. The reduction in clock speed is more conservative than Nvidia’s attempt so despite the GTX590 sporting two more powerful GPUs, this hefty sacrifice may well allow the AMD to take the crown.

Antilles inevitable still follows the VLIW4 architecture Cayman is based on so users can expect to see Morphological AA, and enhanced tessellation performance. Like the previously reviewed ASUS HD6990, the card we are reviewing courtesy of HIS follows the reference AMD design with no tinkering done to the clock speeds or PCB arrangement.

A bit about HIS Digital
HIS – Hightech Information System Limited is an internationally acclaimed graphics cards company. Time and time again, HIS were compared and tested by hundreds of worldly renowned critics. The results are phenomena, HIS have proven to offer far superior, cooler, quieter, and faster graphic cards than any other leading rivals. Up to the fourth quarter of 2008, HIS has won over 700 awards with ATI graphic solution from major media worldwide. HIS is being recognized by providing performance leading and award-wining products.

HIS was established in 1987 with the mission to produce the highest quality PC products in the industry. Besides strong devotion to excellent products and services, HIS has been conducting business with the aim to “Glorifying God”. Honesty and integrity are the two key principals of how HIS are conducted. Ethical business practice has been an everyday commitment to our clients, vendors, and investors.

HIS is proud to be ATI’s Authorized 1st Tier AIB Partner, Certified Partner and Launching Partner. Long term and favorable relationship with ATI, enable HIS to work closely with ATI to promote the HIS ATI Graphics Board; and to strive for best value on the marketing and sales of HIS ATI Product Line.

Let’s see what HIS and AMD have to offer with their card.

Specifications

Antilles, as the HD6990 became known, uses two Cayman GPUs on the same PCB and work via on-board CrossFireX. Cayman is the rightful heir to the successful Cypress core. For the most part, the architecture is much the same with some tweaks to increase efficiency and performance per die size. In this case, the HD6990 opts for the fully enabled XT variant rather than the Pro which found itself on the HD6950. The GPUs still make use of the 40nm manufacturing process from TSMC packing 2.64billion transistors in a 384 square mm die size. Ironically, despite AMD shifting to smaller GPU die sizes, Cayman is their largest GPU since the notorious R600.

Cayman has adopted the VLIW4 architecture over the ageing VLIW5 design dating back to when DirectX 9 was first introduced. The main reason was to increase efficiency in newer DX10/11 titles and to put more emphasis on GPGPU computing. The VLIW4 architecture introduces a narrower Stream Processing Unit, in which the 5th stream processor named the “t-unit” has been removed leaving just 4. Despite the Unit only being able to process 4 operations instead of 5, the advantage is that the space saved allows the core to have more SIMD clusters. The end result is that Cayman can have up to 24 SIMD clusters (24 on the HD6970 and 22 on the HD6950) whereas Cypress only had up to 20 SIMDs (20 on the HD5870 and 18 on the HD5850), giving Cayman a 10% improvement per mm squared compared to previous VLIW5 architecture (as used on Barts also). The architecture is now more catered towards GPU Compute than before and the higher SIMD count also gives additional texturing performance. Each SIMD from both architectures contains 4 texture units so Cayman now benefits from up to 96 units rather than the 80 available on Cypress. Another benefit of the new core is its improved dual 8th generation tessellator that bring up to 3 times the tessellation performance of the HD5870. As mentioned, the Cayman GPUs found on the HD6990 boast the full feature set and all 24 SIMD clusters for a total of 1536 stream processors on each.

With the optional AUSUM (read Awesome) feature disabled (more on this later), the cores are clocked at an impressive stock speed of 830MHz and while this is lower than the stock HD6970 single core speed of 880MHz you have to bear in mind that with two of the cores running at an albeit lower clock speed, they will kick out a serious amount of heat. Also running lower than the HD6970 is the memory speed which is set to 5GHz rather than 5.5GHz (effective). Slower speeds however are however more than compensated because of double the processing power and memory. Each GPU is married with its own 2GB framebuffer for a total of 4GB.

Unlike the GPUs on the GTX590 which end up less powerful than even the GTX570, AMD’s HD6990 does not suffer from such a significant downgrade. This means that the individual GPUs are comfortably superior to the HD6950 and in AUSUM mode, matches the HD6970 except for memory bandwidth. At around £500, the HD6990 is priced closely to two HD6970 but it remains to be seen if scaling will be good in-game.

Product Specifications

Product Code: HIS 6990 Fan 4GB GDDR5 PCI-E DVI/4xMini DP
GPU: HD6990
Core Clock: 830MHz
Memory Clock: 5000Mhz
Memory Size: 4096MB
Memory Type: GDDR5
Memory Interface: 256-bit
Interface: PCI Express x16 (PCI Express 2.1)
Max Resolution: 2560×1600 (Single Display)
DVI Output: 1 (Dual-Link DVI-I)
HDMI: None
DisplayPort: 4 mini DPs 1.2 (2 min-DP-to-DVI adapters supplied)
VGA: Supported using DVI-to-VGA adapter
Crossfire Support: Yes
Power Supply Requirement: 750W

Features

The Excalibur, once owned by the invincible King Arthur, denotes the leader’s mighty kingship with its mystical power and fascinating beauty and brings him triumph battle after battle.

Now HIS raises this sword again for gamers.

The Legend reborn… Prepare to conquer the gaming world!

Get Immersed with AMD Eyefinity Technology
•Featuring 4GB of high-speed GDDR5 memory, the AMD Radeon™ HD 6900 Series is primed to enable ultra-high resolution multi-monitor gaming.
•Expand your favourite games across up to 4 displays with AMD Eyefinity technology for an expansive field of view.
•See more of the battle than ever before with upto 4 simultaneous displays enabling an intense “wrap around” experience putting you right into the game.
•Get the freedom and flexibility to upgrade. This modular solution enables you to add additional displays as you need them.
•Get more done. Put your productivity into overdrive and let up to 4 displays put all the information you need right before your eyes.
•Don’t choose between play and work. Let up to 4 displays help you enjoy games, movies and the web at the same time.

Get Amazing EyeDefinition Graphics with DirectX 11 Technology
•Accept nothing less than the best. With dual GPUs and 4GB of ultra-fast GDDR5 memory, the AMD Radeon™ HD 6990 enables flawless detail and unrivalled performance in the most demanding DirectX® 11 games.
•Harnessing the incredible power of dual GPUs with full support for DirectX® 11 and scalable geometry processing, the AMD Radeon HD™ 6990 is simply the fastest graphics processor in the world.
•With unrivalled frame rates and flawless graphics, the AMD Radeon™ HD 6990 is the definitive solution for uncompromising gamers.
•Leave no performance behind. Take control of the AMD Radeon™ HD 6990 with AMD PowerTune technology, an exceptionally intelligent power management system designed to optimize GPU performance.
•Maximum efficiency. Maximum performance. AMD PowerTune technology in the AMD Radeon™ HD 6990 puts exceptionally intelligent power management under your control.
•Set the bar for beautifully smooth image quality with Enhanced Quality Anti-Aliasing (EQAA) on the AMD Radeon™ HD 6990.
•With quad advanced programmable tessellation engines, the AMD Radeon™ HD6990 is engineered to deliver astonishing geometry processing performance.
•Play your favorite games in full stereo 3D, and get incredibly rich and interactive gameplay with AMD HD3D technology.

Speed Up Applications and Enjoy Brilliant Video with AMD EyeSpeed Technology
•Get more from your system than incredible gaming. AMD Accelerated Parallel Processing (APP) technology taps into the tremendous power of the AMD Radeon™ HD 6990 for stunningly fast applications and pristine video.
•Unleash the most demanding applications with AMD Accelerated Parallel Processing (APP) technology. Do more, faster.
•With world-class support for IEEE 754 double precision floating point ops, the AMD Radeon™ HD 6990 is equipped to dominate computationally intense workloads.
•Perfect your online and Blu-ray video experiences with an unprecedented level of smooth visual quality with AMD EyeSpeed visual acceleration technology.
•Experience Blu-ray 3D exactly as it was intended with AMD HD3D technology.
•Take advantage of Dolby TrueHD and 3D HDTV support in the AMD Radeon™ HD 6990 to create that theatre-quality experience.

Put out Stunning Visual and Unrivalled Audio Experience with HD3D Technology
•Stereo 3D display/glasses support
•Stereo 3D gaming
•Blu-ray™ 3D support
•3rd Party stereo 3D middleware software support
•Launching with AMD Radeon™ 6900 Series GPUs

Microsoft DirectX 11
Enable PC users to enjoy an advanced computing experience and to do more with their PC

AMD Eyefinity Multi-Display Technology
Unlocks the power of GPU’s processor cores to accelerate the most demanding system tasks

AMD CrossFireX™ Technology
Increase your gaming performance with AMD CrossFireX™ Technology

3rd Generation TeraScale Engine
Provides increased processing power for the latest games and accelerated applications

40nm Process Technology
Provides enhanced processor performance while using less power and better transistor efficiency than previous generation technology

Dolly®TrueHD and DTS-HD Master Audio Support
Get a fully immersive high-definition audio experience with the latest Blu-ray movies

AMD PowerPlay™ Technology
Power draw scales according to activity so when GPU activity is low, the power draw is minimal

AMD PowerTune Technology
Maximum efficiency. Maximum performance. AMD PowerTune technology in the AMD Radeon™ HD 6990 puts exceptionally intelligent power management under your control

Enhanced Unified Video Decoder (UVD) 3
Watch the hottest Blu-ray movies, online video and other HD content beyond 1080p with low power and low noise with GPU acceleration and enhanced Unified Video Decoder (UVD) 3 features

Packaging and Content

The front and back of the box

HIS have gone with their traditional upright packaging to house their latest high end HD6990. Apart from the length, it is no different to the packaging used on the previously reviewed HD6950. The box is vivid with colour and the depiction of the sword is reminiscent of their Excalibur theme. Their Excalibur branding has always been recognised amongst enthusiasts and represent their seal of high performance. Amidst the beautifully patterned background, HIS have provided several features and benefits of their graphics card. At the top, their logo is displayed with the “Faster, Cooler, Quieter” tagline symbolising their key philosophies. It waits to be seen if the card lives up to these expectations. At the bottom, illustrations show a few of the features the card supports including the actual name of the card, the HD6990. We also note that the card sports a 4GB GDDR5 framebuffer, 2GB for each GPU working in parallel. The back is home to a vast amount of further detail.

The AMD features

The patterned theme carries on throughout the box. Turning to the back, the box is rich in information concerning the features of the card. At the top, HIS highlights AMD’s Eyefinity and related visuals technologies such as support for DX11 and 3D gaming, dubbed EyeDefinition and EyeSpeed. A table displays all the rest of the key features and their respective benefits to users. The HD6990 also supports up to 6 monitors in Eyefinity thanks to its plethora of on board connectors.

The features and benefits

Closer to the bottom are small illustrations indicating compliance to HDMI 1.4, OpenGL 3.2, PCIe 2.1, 7.1 audio and several others. The features are clear and easy to read with a gaming feel to appeal to consumers. The table lists all the features and benefits of the graphics card.

The inside box

Upon opening the main box, we are greeted with another grey box within which the rest of the bundle and graphics card can be found.

The bundle

The top compartment is reserved to the accessories and installation guide. Included are:

– 2 Dual MOLEX-to-6-pin PCIe power cables
– 1x DVI-VGA adapter
– 1x Active Mini DisplayPort to Single-Link DVI dongle
– 1x Passive Mini DisplayPort to Single-Link DVI dongle
– Installation CD
– Quick installation guide
– Multilingual User guide
– HIS Power Up label

Unlike the ASUS variant, no mini-DP to DP adaptors are present. Neither bundle CrossFireX bridges which is usually standard on other cards. It’s good to see HIS bundle the Display Port to DVI adapters which AMD are actively pursuing their vendors to do in order to drive the standard forward. Since Eyefinity requires at least one monitor with DisplayPort, one active adapter is provided for the functionality to be supported.

The graphics card inside the box

Below the bundles compartment lies the attractive looking graphics card in its own plastic cover for added protection.

Closer Look

The graphics card

Rather than curvaceous lines of the GTX590, AMD and HIS in this case have settled for a no-nonsense box shaped design that is made appealing by its metallic finish and the blue Excalibur sticker. It is reminiscent of other reference cooled HD6990 but it still retains the sleek look we have grown accustomed to with AMD reference cards. The card is a hefty 30.5cm in length so buyers need to be wary before purchasing. The card’s most distinctive feature is its centred position fan, similar to Nvidia’s GTX590 despite the clear difference in fan design.

On its side

The sheer size is apparent when removed from the packaging. At 1kg in mass, puny is the last word you’d use to describe and thankfully this is all attributed to the cooling employed to tame the two beasts within.

The back of the card

At the back, the graphics card sports a 1.5mm thick metal back plate for additional cooling and to provide structural support when installed inside. The heatsinks are secured by x-shaped brackets and 4 spring loaded screws to ensure good heatsink contact with the GPU and added pressure. The areas behind the GPUs have been left exposed since the circuitry is raised slightly higher than the rest of the components. The two rubber spaces at the edge of the card are presumably to prevent a second card above it from drooping under its weight. By allowing a small gap between two cards in CrossFire, the top card receives better airflow.

The fan

The HD6990 uses a centre positioned blower type fan. Rather than placing the fan at the end whereby one GPU ends receiving warmer air from the other, this placement allows air to be blown evenly onto both heatsinks on either side. The blower type fan is more effective at pushing air sideways across the heatsinks but unlike the bladed GTX590 fan, it is harder to draw air in. The fan is only slightly smaller than the 80mm fan on Nvidia’s GTX590. HIS have opted to place their brand sticker onto the fan rotor. Again, the single fan has the arduous task of cooling two already hot running GPUs. The fan has PWM functionality and its speed can therefore be controlled manually or automatically through a temperature profile.

The rear exchaust vent

Inevitably, the downside of the cooling solution is that air is exhausted from either end of the graphics card. On this side, hot air will be pumped back through the vent into the case so adequate airflow is necessary.

The side profile

On the side of the shroud, we see the ribbed design that has been characteristic of AMD’s mid and high end cards this generation. They follow AMD’s black and red colour theme.

The two 8 pin PCIe power connectors

Like the GTX590, the HD6990 makes use of 2 8 pin PCIe connectors to achieve its substantial 375W TDP. Each connector can draw 150W from the 12V rails and the PCIe slot provides an additional 75W for a total of 375W. Although HIS bundle two Molex to 8 pin adapters, it is highly recommended to buy a power supply from a reputable brand which should come with dedicated 8 pin PCIe cables. Should you find yourself needing adapters, it is a sign that you need a new power supply. The connectors are ideally situated on the side of the card to avoid conflicts with HDD cages or other components given the already lengthy size of the card.

The CrossFire connector and BIOS switch

A single CrossFire connector is built onto the card because CrossFireX is currently limited to 4 GPUs. Since the HD6990 already has two, an additional connector is not necessary. Most will probably find the HD6990 enough for their gaming needs regardless of settings.

Previous incarnations of a physical, switchable BIOS switch were seen when the 6900 series first appeared on the scene. These BIOS switches enabled the end user to have a ‘stock’ BIOS and a further BIOS which could be edited by the user to setup the card how they wished. This time however, AMD have seen fit to pre-overclock a second BIOS on your behalf allowing you to run the card in either stock or overclocked formats. The stock speed of 830/5000 is attained in position 1 with a voltage set to 1.12v, while position 2 increases this voltage to 1.175v allowing the clock speed to be raised to 880/5500. Also known as AUSUM mode, the second BIOS increases the TDP to 450W by increasing the PowerTune limit by 20%, which can also be set manually via AMD CCC Overdrive. 450W is beyond the rated specification of the 8 pin connectors but they will certainly cope as long as the power supply is branded and up to the task. If nothing else, it’s a welcoming change from the restricted GTX590.

The I/O plate

As the ASUS HD6990 is a reference design, it matches the AMD specification for display outputs. From left to right there are four mini-DisplayPort connectors and a single DL-DVI port supporting up to 2560×1600 single resolutions. The five connections allow five screens to be supported. Should you have a Multi-Stream Transport hub (MST), a sixth screen can be added to complete that Eyefinity setup you have dreamed of. The main advantage of the new DisplayPort standard is the double bandwidth over the previous 1.1 ports, taking it from 10.8Gbps to 21.6Gbps. In real world applications, it means that a single port can support up to 2 2560×1600 monitors and 4 1920×1200 monitors through daisy chaining or by using the MST hub. Unlike the HD6970/HD6950, no HDMI ports are present and HIS haven’t bundled an adapter. It highlights AMD’s aim of driving the DisplayPort standard into the mainstream. The top is of the I/O plate is completely vented to exhaust as much hot air outside of the case as possible.

Closer Look (Continued)

AMD HD6990 VS HD6950

With the two cards sitting next to each other, the size difference between the single and dual GPU cards is apparent. At 30.5cm, the HD6990 is 3.1cm longer than the reference HD6970/6950. In terms of styling, both follow the same shroud design. The fans are positioned differently with the HD6990 sporting a slightly bigger one.

Nvidia GTX590 VS AMD HD6990

The HD6990 is also longer than Nvidia’s dual GPU alternative by 2.2cm. It is also clear that the fan on the Nvidia card is larger in diameter and a down-draft rather than the blower type on the HD6990.

Removing the back plate

Removing the back plate reveals the network of circuitry that dominates the PCB. None of the PCB real estate has gone to waste in AMD’s attempt at creating a stable and efficient graphics card. There are a total of 8 256MB memory modules on the rear split into two groups on either side of the board pertaining to the two separate GPUs. Unlike the GTX590, there is symmetry in the board design. Thermal pads on the back plate provide additional cooling to the memory modules.

The shroud and cooler

Removing the shroud reveals the fin based blower fan placed between two large vapour chamber coolers for each heatsink. The fan uses a standard 4 pin PWM adapter. A metal bracket holds both heatsinks and provides additional cooling to the PCB components. In fact, the bracket has a distinct grill shape in the middle to maximise dissipation surface area.

The vapour chamber cooler

Both GPUs are independently cooled by a 37 aluminium finned heatsink that dissipate heat from the underlying vapour chamber. The copper heat plate contains liquid in the base (the raised middle part of the plate that is in contact with the GPU). The liquid evaporates and absorbs further latent heat through its phase transition to vapour. This rises and condenses on the outside upper part of the heat plate releasing heat which is then transmitted to the overlying fin array whilst the condenser fluid circulates around the outside of the heat plate. These types of coolers have proved very efficient in the past so we expect more of the same on the HD6990.

The base of the cooler

The underside of the cooler and shroud uses a metallic construction and sports more thermal pads to cool the rest of the memory modules. An additional thermal pad cools the ATI CrossFire bridge chip. We also see that the base of the vapour chamber coolers is copper for more efficient heat transfer.

Closer look at the fan

The fan looks very simple in design but we are confident that AMD know what they are doing. The circular ring above the fins prevents vibrations and a more stable fan.

The bare PCB

Finally, we have the PCB itself. The design has rotational symmetry which helps manufacturing costs and ensures same length traces from the VRM circuitry to each core. The ATI CrossFire chip is off centre to make way for the power regulators.

Closer Look (Continued Part 2)

The first GPU

Here we have the first Cayman GPU, surrounded by 4 256MB memory modules. We have to remember that there are an additional 4 on the underside for a total of 2GB per core.

Behind the first GPU

And here we see the other 4 modules linked to the first GPU. The module placement uses an alternate pattern with one module being on one side and the adjacent module being on the other.

The second GPU

The second Cayman GPU reflects the same design as the first. 4 memory modules surround the GPU and a further four on the underside of the PCB for a total of 2GB.

Behind the second GPU

Again the memory modules are arranged using an alternate pattern. The X-bracket uses 4 spring loaded screws for good mounting pressure. These have to be removed if you want to take off the cooler and shroud for whatever reasons. Doing so is not recommend as it voids the warranty and at Vortez, we take the graphics card apart to show you exactly what lies under the hood to save users the trouble of finding out for themselves.

Cayman

The GPU have a slightly different model number to the ones on the HD6970 to differentiate their clock speeds. The Cayman core seen here has a die size of 389 mm squared, significantly larger than the 255mm squared Barts core and the 334mm squared Cypress core. This is the largest AMD core since the notorious R600 core design which came at 420 mm squared. The fabrication is still on the 40nm process due to the lack of readily available 32nm or 28nm manufacturing.

The PCIe bridge chip

The PCI-Express bridge chip is the same specification of the HD5970 which is also manufactured by PLX but still has the old ATI insignia, possibly because the chip is from the parts bin of previous graphics cards. This bridge chip is fully compliant with PCIe 2.1 x16 specification, so can provide enough bandwidth per core regardless of the strain they are under.

The Hynix memory modules

The memory modules are once again GDDR5 chips sourced from Hynix rather than Samsung. The H5GQ 2H24MFR T2C 039A chips operate at 1.5V. The T2 denotes that the memory is rated at 5GHz but as we will see later on, this is a very conservative clock speed. Each of the 16 modules are 256MB totalling 4GB, 2GB for each core. These are the same modules found on the HD6950.

The power circuitry

The CLA1108-4 chokes provide a 4 phase VRM design to each core as denoted by the MOSFETs. The design is similar to that on the HD6970/6950 but is not as robust as the latter’s 6 phase PWM design. Each set of memory modules for each core are reinforced by a 2 phase power circuitry.

The two voltage controllers

The two Volterra VT1556MF voltage controllers are the same ones used on other reference HD6900 cards meaning that voltage tweaking is supported using MSI’s latest version of Afterburner.

Test Setup

CPU – Intel Core i7 920
RAM – 6GB (3x2GB) OCZ Platinum DDR3 1333MHz
Motherboard – ASUS Rampage III Extreme
Power Supply – Enermax Revolution 85+ 850W
Hard Drive – OCZ Vertex 2E 120GB
Samsung F3 1TB
Samsung F1 320GB
Cooler – Noctua NH-C14

Graphics Cards:

HIS HD6990 4096MB @ 830/5000MHz, 880/5000 AUSUM & 950/6000 Overclocked – ATI Catalyst 11.4 (8.840.3.0)

ZOTAC GTX590 3072MB @ 607/3414MHz & 670/3804MHz Overclocked – Forceware 270.61

Inno3D GTX560Ti 1024MB @ 820/4008MHz & 950/4300MHz Pre-overclocked – Forceware 266.66
Inno3D GTX570 1280MB @ 732/3800MHz, 800/4000MHz Pre-overclocked & 901/4220MHz Overclocked – Forceware 263.09
ASUS GTX580 1536MB @ 782/4000MHz & 903/4220MHz Overclocked – Forceware 262.99
ASUS HD6970 2048MB @ 890/5500MHz & 949/5896MHz Overclocked – ATI Catalyst 11.4 (8.840.3.0)
HIS HD6950 2048MB @ 800/5000MHz & 865/5500MHz Overclocked – ATI Catalyst 10.11 (8.790.6.0, 8.790.6.2 & 8.800)
Nvidia GTX480 1536MB @ 700/3696MHz & 799/3906MHz Overclocked – Forceware 260.99
MSI R6870 2PM2D1GD5 1024MB @ 900/4200MHz – ATI Catalyst 10.10
XFX HD5870 1024MB @ 850/4800MHz & 942/5200MHz Overclocked – ATI Catalyst 10.10

Benchmark Suite

MSI Afterburner & Kombustor
ASUS SmartDoctor
GPU-z
Crysis Warhead using the FRAMEBUFFER Crysis benchmark tool
Far Cry 2
Metro 2033
Resident Evil 5
Street Fighter IV
Unreal Tournament 3 using the HOC Bench tool
Colin McRae DIRT 2
Batman: Arkham Asylum
Battlefield Bad Company 2
Mafia II Demo
Colin McRae DIRT 2
Alien VS Predator
H.A.W.X 2
3DMark 11
3DMark Vantage
Unigine V2.1 DX 11 Benchmark

Software Bundle

The bundled disc is fairly standard and doesn’t come with many applications or software which we have grown accustomed to. This is not necessarily a bad thing as most tend to be available on the internet anyway.

In terms of utilities, HIS bundle a multi-monitor management software known as Hydra-vision. These are already implemented in the Catalyst Control Centre so there is no need to install the utility separately.

AMD PowerTune

Overclocking is nothing without stability and for most enthusiasts; applications such as Furmark, OCCT or MSI Kombustor have been the stress test of choice to truly load graphics cards. However, both AMD and Nvidia have voiced their concerns against the use of such applications due to the number of cards killed as a result of high temperatures and unforgiving load. They believe that stress tests are not representative of gaming loads and should therefore not be used as an indicator for stability.

This is where PowerTune comes in. The basic concept is that it locks the GPU’s thermal design power (TDP) to a pre-determined value such that when it is exceeded, the GPU will try to lower power usage. This is achieved by simply lowering the clock speed when the pre-determined TDP is attained under load. On the HD6950 and HD6970, we saw the PowerTune Maximum Power set to 200W and 250W respectively. AMD claim that typical gaming loads would draw 140W using the HD6950 and up to 200W using the HD6970, meaning that in typical scenarios, gamers shouldn’t worry about their cards reaching the maximum TDP and throttling. The HD6990 inevitably has a much higher TDP so the PowerTune Maximum power has been set to 375W which is representative of the rated power draw from the PCIe slot and the two 8 pin connectors. The main situation where it PowerTune would kick in is under heavy loads from programs such as the stress test applications mentioned above.

Overclocking presents another scenario where throttling might occur. Not surprisingly, overclocking will increase the power draw both in game and in stress tests closer to 200W/250W on the single GPU AMD cards. This means that the card will be more susceptible to throttling as they exceed the PowerTune maximum TDP. AMD realise that PowerTune may not appeal to overclockers but rather than giving them the option to disable the feature, they provide power control settings in Overdrive. Raising the limit to 20% sets the new maximum TDP to 240W on the HD6950 and 300W on the HD6970, still within ATX specifications. On the HD6990, the maximum TDP is set to 450W. AUSUM mode automatically sets the TDP to the higher value to account for the higher clock speeds it sets the GPU to. This gives overclockers additional headroom and performance before throttling occurs. It also means that at stock clocks, the chance of getting reduced performance is much less. Conversely, to increase power efficiency, the power control settings can be reduced by 20%, making it ideal in situations where higher clock speeds are not needed.

In some ways, the system is akin to Turbo mode on both AMD and Intel CPUs. In the latter case, if power draw is within the TDP, the CPUs will have their speed boosted. Therefore, under light load, the CPUs will operate faster and simply clock to default speeds when the TDP is reached. In the HD69XX’s case, the core works at its default clocks and throttles when the TDP is reached. Nvidia have employed a similar feature on their GTX580/570 for the same reasons as AMD.

Throughout the benchmarks, the PowerTune limit was set at 20% to ensure overclocking headroom. However, at stock speeds, there was no noticeable performance difference between the 0 and 20% settings.

Temperature & Overclocking

As power hungry as Cayman can be, AMD were very conservative when reducing the clock speeds to meet the 375W TDP. As such, both GPUs come clocked at 830/5000MHz by default, 50MHz less than the HD6970 on the core and 500MHz less on the memory due to the lower rated modules used. At stock, the load voltage is 1.12V, a smidgen higher than the stock HD6950 but much lower than the HD6970 which operates at 1.175V. At idle, one core clocks down to 450MHz while retaining the same memory speed whereas the second core clocks to 250/600MHz to minimise heat output. Due to two screens being used, the first core did not downclock as much. At these clocks the first core operates at 0.9V and the second one operates at 1.0V.

Stock

Unique to the HD6990 is a BIOS switch that overclocks the card and increases the card’s TDP in accordance. Dubbed AUSUM, it raises both core clocks to 880MHz to match that of the HD6970. The memory speeds remain intact. To ensure stability, the core voltage also increases to 1.175V under load. Idle voltages is unchanged as are the idle clock speeds.

AUSUM

Previously reviewed HD6970s have been somewhat disappointing when it came to overclocking, apart from MSI’s Lightning of course. So I was pleasantly surprised by the HD6990’s headroom, especially considering the power and thermal limitations. In the end, a clock speed of 941/6000 was achieved by increasing the voltage to 1.205V. When overclocked, the first core clocked down to 500MHz instead of 450MHz at idle, with the voltage not changing from load. The second core still clocked down as before and operated at 0.9V.

Overclocked

AUSUM mode represents a 6% overclock on the core which translates into the same pixel and texture fill rate performance boost, as is the case for the shader operations. A further 6.8% overclock was achieved on the core representing a 13% total overclock over stock speed. The increase in theoretical performance mirrors this overclock. Impressively, the 5GHz rated memory modules managed 6GHz, a 20% increase in bandwidth.

In real world testing, the AUSUM clock generates a mere 2% performance boost over standard clocks and overclocked performance is 6.5% more than the reference clock. Performance does not scale linearly with overclocking suggesting that PowerTune may have throttled the card under high loads.

Temperature

There’s no denying that the HD6990 is a hot running card but it gets off to a decent start at stock speeds. A 64/66C delta is in line with other high end single GPU cards. This was achieved by the fan operating at 48% which was definitely audible but not intrusively so. The second core idled with a high temperature delta even when clocked down. In AUSUM mode, the load delta temperate rose by 2C and the fan began to work much harder to tackle the heat output. Working at 61%, the noise became very intrusive and could only be drowned out by loud music or games. Overclocking yielded very high delta temperatures. It ended up hotter than the GTX590. When gaming, the fan speed ramped up to 80% and even 100% after prolonged sessions making the card unbearably loud. The noise from the fan speed increase closely imitated a jet fighter taking off and this is no exaggeration. Thankfully, the card remained quiet at idle. Between the GTX590 and itself, the former was easily more bearable to use for everyday gaming.

Crysis Warhead

Following the success of Crysis, the stand alone expansion “Warhead” was hotly anticipated to bring more game play, more weapons, improved visuals whilst maintaining better performance, the latter being what gamers wanted most. After all how many people upgraded their rigs just to play this game… In the game, you play as the upbeat Brit Sergeant “Psycho” Sykes, chasing down a Korean nuclear warhead. Throw in some ice shooting aliens and we’re bound to have a great game. It sure delivered.

Testing was done using Framebuffer’s Crysis Warhead benchmarking tool. The tests were configured to DirectX 10 at Enthusiast levels. Each test on the Ambush map was looped three times from which the average FPS was recorded.

The HD6990 performs extremely well with high levels of AA and at the highest setting, the penalty is minimal.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Far Cry 2

One of the most hyped games of 2008, Far Cry 2 had some big shoes to fill. It was built to be the next best thing since well… Far Cry I suppose. Combining an open-world game play with highly detailed graphics, physics and AI, what more could we possibly want? The game puts us in the body of a malaria inflicted mercenary hunting down the “Jackal” in the heart of Africa, in a bid to stop an on-going conflict between two rival factions. The storyline can be hard to follow sometimes but I’m no game reviewer, so let’s concentrate on the graphics and performance. After all, we all need to know if our hardware will be able to handle the scorching savannah burning at the hands of our flamethrowers.

The bundled benchmarking tool was used on Far Cry 2, configuring the settings to Ultra and DX10. The small ranch level was chosen and each configuration was looped three times from which the average FPS was recorded.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Metro 2033

Based on Novel by the same name, Metro 2033 is a first person shooter with elements of survival horror. As Artyom, you trawl through the mutant infested metro systems of post-apocalyptic Moscow. The game delivers presents a grim ambience that reflects on the overall atmosphere of the underground setting. Metro 2033 uses the setting as a back drop to showcase some of the best visuals of any games out now, making it the ideal benchmark for those looking for the best graphics card.

The bundled benchmarking tool was used on Metro 2033, configuring the settings to Very High and making use of DirectX 11. The frontline scene was looped 3 times for each configuration. The average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Resident Evil 5

Resident Evil 5 is the sequel to the Resident Evil series, exploring the life of main protagonist, Chris Redfield. You play as either Chris Redfield or Sheva Alomar in an African desert area in Kijuju. In true Resident Evil fashion, your main objective is to investigate a terrorist bio-organic weapon threat whilst killing infected “Majinis” on your way.

The Resident Evil 5 benchmark tool was used to test performance. All settings were set to the maximum possible and the average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Street Fighter IV

Street Fighter is back in its 4th iteration and it’s bigger and better than ever. Combining fluid, fast based sparring with stunning artistic visuals, the game delivers tremendous game play. Be reacquainted with some of the most popular characters in video game history while you battle your way to the top, be it with Ryu or the mighty Bison. The game might be frustratingly hard in some cases but there’s nothing like the satisfaction of K.O’ing your opponent with a well stringed death bringing combo.

The Street Fighter IV benchmark tool was used to test performance. All settings were set to the maximum possible and the average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Unreal Tournament 3 & Batman Arkham Asylum

Unreal Tournament 3

Built around the unreal 3 engine, Unreal Tournament is all about mindless fast paced shooting, decapitation with a plethora of game modes to so in. Not much else can be said really except that it promises hours of enjoyment on multiplier whether it be against bots, your friends at a LAN or online. It was one of the more popular games out there to adopt PhysX in the form of partially destructible maps, tornadoes and hail.

The Hardware OC UT3 benchmarking tool was used to test the game. The maximum in game settings were used including motion blur. Anistropic filtering was set to 16x and no Anti-Aliasing was used. The Containment was benchmarked and the average FPS recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Batman Arkham Asylum

The Dark Knight takes on his greatest challenge yet when he becomes trapped with all of his most dangerous villains inside the insane asylum of Gotham City – Arkham Asylum. The game exposes you to a unique, dark and atmospheric adventure that takes you to the depths of Arkham Asylum, Gotham’s psychiatric hospital for the criminally insane.

The in-game benchmarking tool was used to test performance. All the display settings were set to very high. No AA was used and PhsyX was only enabled if specified in the charts. The average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Colin McRae DIRT 2

DIRT is back and it’s bigger than ever. With an onslaught of famous X-Games competitors such as Ken Block and Dave Mirra, extreme is being brought back to rally. The game not only delivers outstanding gameplay in lush environments but also stunning visuals in the form of Direct X 11 implementation. If you want some fast paced, arcade style racing, then look no further than Colin McRae DIRT 2.

The in-game benchmarking tool was used to test performance. All the display settings were set to the maximum available and DirectX 11 was applied. The average FPS was recorded at the end.

The high framebuffer means that at 8xAA, the performance drop isn’t as significant as on the GTX590. The HD6990 copes very well at extreme settings although a high resolution display would have been ideal to push it further.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Battlefield Bad Company 2

Battlefield Bad Company 2 is the new rendition of the widely successful Battlefield series of game. Having more in common with the console release of Bad Company, the sequel hopes to inject the DNA of the timeless Battlefield 2 online experience with the witty action packed single player shooting adventure of the original. As Private Preston Marlowe, your goal as a member of Bad Company is to once again save the world by securing a scalar weapon device.

Fraps was used to test performance. Each test was conducted at the start of the ‘Upriver’ level ensuring that the same actions and paths were taken during the 2 minute sample. All settings were set to the highest available in game with AF set to 16x and HBAO turned on. The average FPS was recorded by FRAPS at the end of each walk through.

Again we see the HD6990 coping very well under high settings and does not suffer from the same relative performance hit as the Nvidia card.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Mafia II Demo

Following the success of Mafia back in 2002, the third person action adventure game is back with a new grittier and darker world. As Vito Scaletta, an aspiring made man, your job is to work through the twist and turns of Mafia lifestyle. The more blood spilt, the more you get in return but the lifestyle was never meant to be an ideal one. Set in the visually stunning Empire City, the wartime references provide the ever present back drop to a rife period in America’s history, in which potential for exploitation becomes Vito’s key focus.

The in-game benchmarking tool was used to test performance. All the display settings were set to the maximum available in-game. PhsyX was only enabled if specified in the charts. The average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Alien VS Predator

Spawned from the popular Alien and Predator franchises, Rebellion have collaborated to bring the legendary war to us through the medium of a first-person shooter. The game forces you to hunt, prey and most importantly survive in the swamp colony of Freya’s prospect as a Predator, Alien or Marine. The stunning visuals add to the sense of dread and terror that we have become so accustomed to seeing with the series.

The stand-alone Alien VS Predator benchmark tool was used for testing here. All the settings were set to very high and Tessellation was applied. The average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

H.A.W.X 2

Tom Clancy’s H.A.W.X. 2 is an arcade-style flight action game from Ubisoft. H.A.W.X.2 is DX11 ready and therefore like other simulators such as DIRT2 has stunning scenery and a truly breath-taking visual experience. Using hardware terrain tessellation, H.A.W.X.2 relies on raw GPU power because a series of detailed triangles are required to be rendered. This surely has to be one of the most taxing benchmarks all our featured games, H.A.W.X.2 presents some of the best tessellation execution in any title to date.

The in-game benchmark from the demo was used fort testing. All the maximum settings were used throughout testing. The average FPS was recorded at the end.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

3DMark 11 & Vantage

3DMark Vantage

This Vantage benchmark suite from Futuremark introduces DX 10 & PhysX support. Despite being on the verge of DX 11 games arriving, Vantage still proves a popular testing ground for enthusiasts.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

3DMark 11

Finally here is the latest Futuremark benchmark suite, bringing DX11 and tessellation to benchmarkers. Will it bring your computers to their knees?

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Unigine V2.1 Benchmark

Unigine’s benchmark is to showcase the benefits of DX 11 and the use of tessellation as opposed to normal rendering techniques. The demo has impressive visuals that give an insight into what we can expect from gaming in the future.

Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings and resolutions used in-game.

Overall Performance Analysis

The overall performance analysis looks at the relative performance between all the cards on test across all the settings used in our benchmark suite. For an explanation of our benchmarking procedure, have a look at the descriptions on each test page.

AMD have done a tremendous job with the HD6990 and its performance reflects this. Although the GTX590 edges slightly ahead overall, there are many factors to consider. If we disregard HAWX 2 which is highly biased towards Nvidia, then AMD take the overall performance crown. This is a significant feat because the single GPU AMD cards have always found themselves behind Nvidia’s alternatives. Both companies have opted for two of their highest end GPU and placing them on the same card and yet the Cayman based card generates much better scaling despite being inferior to Nvidia’s GF110 GPU on its own. CrossFire scaling was 55% over the single card performance and 59% when in AUSUM mode, significantly higher than demonstrated by the GTX590. This is certainly very impressive especially when we consider that the card was hardly being pushed to its limit. We expect scaling to be much better at higher resolutions and scaling as shown below. Games such as Crysis Warhead, Metro 2033, AVP, Battlefield Bad Company 2, HAWX 2, 3DMark 11 and Unigine saw scaling upwards of 70% over a single HD6970. Bad Company 2 and Unigine demonstrated scaling of around 85%, an impressive result considering the popularity of the former. In the other games where CrossFire scaling was lacking, performance was still high enough and any gains would have been unnoticeable regardless of the setting used.

Resolution Scaling

As we expected, dual GPU scaling was much better at higher resolution. This is partly attributed to the higher framebuffer on the AMD cards as we can observe when comparing the relative performance of the HD6970 to the Nvidia cards. The other reason is that games become much more GPU dependent at higher settings. It was pleasing to see that under most circumstances, the GPU usage on both cores were 100% especially with higher loads. The usage did not fluctuate like GTX590 experienced.

Power Consumption

AMD recommend a 750W power supply with 42A on the 12V rail at least to run their HD6990 and after seeing the load power draw, it is advisable to listen to AMD. At the default speed, the power draw matches a GTX480 and is only 20W higher than an overclocked HD6970. This is very impressive from a performance per watt perspective. AUSUM mode increases the power draw significantly due to higher clocks, voltage and increased PowerTune TDP. It ends up less efficient than an overclocked GTX590. Overclocking the HD6990 only increases power consumption further, but not on the same extent as before implying that the card’s TDP was being met and consequently the card was throttled.

Conclusion

AMD’s HD6990 was nothing short of outstanding throughout testing. Dual GPU cards have come a long way since Nvidia’s 7900GX2. The main problems that have plagued such designs have been game support, constant reliance on drivers, micro-stuttering, sub-par scaling, costs, heat output and power consumption. The HD6990 tackles a lot of these issues and our performance results demonstrate how effective it really is. Most games tend to ship with CrossFire/SLI support nowadays and the HD6990 users no longer have to wait for the feature to be implemented. This means that they can happily buy the latest releases without the fear of their card being unsupported. The worse-case scenario is that AMD have to update their drivers but monthly releases and hotfixes ensures that support is prompt. As we see throughout benchmarking, all the GPU intensive games show remarkable scaling with two cores and those that didn’t were already churning out over 100 FPS on single GPU cards that it didn’t matter whether the HD6990 worked to its full potential. Most importantly, no micro-stuttering was observed and games played smoothly. Performance wise, the card delivered and was easily on par with Nvidia’s GTX590 alternative and its higher framebuffer gave it the edge at higher settings. This brings us to our next point.

There are several reasons why people might opt for dual GPU cards over two separate cards; i) motherboards only have one PCIe x16 slots, ii) power supplies lack the necessary cables, iii) cost, iv) they want a quad GPU setup. The first two considerations are somewhat irrelevant because we expect enthusiasts looking for the ultimate performance to have CrossFire enabled motherboards already and a branded high power rated PSU. That leaves us with the next important factor, cost. Ideally, a dual GPU card should cost less than the dual card alternative due to lower manufacturing costs although that may be partially offset by development costs. In the past, this has typically been the case but in this case, the price benefit isn’t as clear cut. Looking on the web, prices of the HD6990 tend to fluctuate regardless of brand and in the best case scenario they are priced under £500 making it £250 per GPU. This matches the cost of two separate HD6970. The advantage of the HD6990 is that power consumption is lower but the downsides included higher temperatures, noise and slightly reduced clock reference clock speeds. Our example from HIS has demonstrated that the lower clock speed can easily be corrected by simply overclocking and the GPUs certainly have a lot of headroom. But the problem is that it is much easier to reach the card’s TDP limit and often the card will be throttled. Single cards are less susceptible to this problem. So we end up with a card that favours lower power consumption but consequently limits performance compared to running two separate cards. However, there have been several offers with the HIS HD6990 being retailed at a more appealing £450 price point in the past which makes the card a very viable option.

The main downside of the HD6990 is the noise. More times than often, I found myself simply turning off a game because the fan noise became unbearable. Simply turning up the in-game volume was not enough to drown the card’s noise and after longer periods of time, the fan would easily ramp up to 100% where it imitated a jet fighter taking off! For day to day use, it idles silently but gaming is the card’s purpose and at that, it ends up more of a distraction than a tool. If noise does not concern you and you use headsets, then you have one less reason not to buy a HD6990.

Like the GTX590, it is tough to conclude such a product. There’s no denying that it boasts an immense amount of power and no games will drag it to its knees. It’s when you factor in the alternatives and the downsides that you get a clearer understanding of the card. It is easy to be completely infatuated by the performance of the card and simply give out the best award but in this case, the HD6990 falls slightly short of what we deem worthy of our coveted gold award. Personally, the only reason to get the HD6990 is you are looking to get a quad CrossFire setup or a dual card setup is somehow unfeasible.

HIS themselves have done a good job with their offering. It comes with a number of bundled extras and their added touch adds to the aesthetics.

Pros
+ Class leading performance
+ Brilliant CrossFire scaling
+ Excellent tessellation and AA performance
+ Out of the box Eyefinity support
+ Large framebuffer
+ Well packaged
+ Aesthetics
+ Good overclocking headroom

Cons
– Size
– Noise
– Cost

As summed up by Richard in the ASUS HD6990, had the price been more comfortable and the cooling solution more adequate, the HIS HD6990 would have easily earned our coveted Gold Award. Unfortunately, it has to settle for our Silver Award.