ASUS HD6950 2GB DirectCU II Review

ASUS are bringing their latest DirectCU II innovation to their line-up of graphics cards. Let’s see how it fares the AMD HD6950.

Product on Review: ASUS EAH6950 DCII 2DI4S/2GD5
Manufacturer and Sponsor: ASUS
MSRP: N/A
Street Price: £249.95

ASUS have always been at the forefront of innovation across their vast catalogue of computer hardware and components. We only have to look at designs such as the ASUS ARES HD5970 and their flagship Rampage III Extreme to grasp the level of technical expertise in the ASUS labs. The common factor distinguishing them though has always been their prices in the retail market. This has limited such products to the enthusiasts capable of digging deep into their pockets, if only for the sense of exclusivity amidst the performance and features offered by these high end products. But in many cases, ASUS have been careful in selecting some of their best innovations and trickling them down to mainstream consumers, whether it is in the form of better component usage or introducing features such as BT GO as found on their P67 line of motherboards. The graphics card we have for review today is an example of how their expertise in graphics card cooling is being brought to a wider audience. We have previously seen ASUS use their DirectCU coolers on a limited selection of mid-range graphics card such as the AMD HD6850 and the HD5850. The DirectCU coolers proved to be very efficient in terms of thermal performance and noise levels. Somewhat counter-intuitively in this case, ASUS have evolved on the technology to make it applicable to higher end graphics cards. The result is the new DirectCU II dual fan cooling solution. In its triple slotted form, ASUS have introduced the cooler to their GTX580/570s and their HD6970/6950s while its dual slotted form appears on the GTX560 Ti. The true innovation however doesn’t lie in the cooler itself but in the use of “Super Alloy Power”, demonstrating their efforts at broadening their technology to the masses.

The graphics card we will be focussing our attentions on today is the HD6950, which we covered in great depth on release. The Cayman GPU that the card is based on features AMD’s new refined VLIW4 architecture, boasting a total of 96 texture units, upgraded render back for improved anti-aliasing performance, and an enhanced tessellation engine. The HD6950 only features 88 of those texture units and 1408 stream processors out of a potential 1536 which the fully unlocked HD6970 sports. The main advantage is significantly reduced power consumption, making the HD6950 a very capable card.

ASUS have enhanced theirs by applying their standard 10MHz pre-overclock to their HD6950 and bundling their voltage tweaking SmartDoctor utility. The card ends up clocked at 810/5000MHz by default with a 2GB framebuffer on top for abundant bandwidth. Most notably are of course the brute looking DirectCU II cooler and the new VRM circuitry on their customised boards. To adhere to their overclocking pedigree, the HD6950 comes with a second 8 pin power connector rather than a 6 pin one for improved headroom. On initial impressions of this beast, it looks to be promising.

A bit about ASUS:

ASUS comes from the last four letters of Pegasus, the winged horse in Greek mythology that represents the inspiration of art and learning. ASUS embodies the strength, creative spirit and purity symbolized by this regal and agile mythical creature, soaring to new heights of quality and innovation with each product it introduces to the market.

ASUS pursues technological and aesthetic perfection through continuous innovation. We place ourselves in our customers’ shoes to develop a deep understanding of, and genuine empathy for, their needs—enabling us to create user experiences that transcend the norm.

ASUS Design Philosophy

ASUS Design develops high-quality solutions our customers will enjoy.
Our design process is built on thorough research, early anticipation and well-planned execution.

We act with a global vision and a focus on local strengths, conditions and heritage.

Let’s see what ASUS has in store for us with their latest monster.

Specifications

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. The GPU comes in two variants, Cayman Pro and Cayman XT, the former found on board the HD6950 and the latter on the HD6970. Originally, the Cayman core was poised to be manufactured on the 32nm manufacturing process which would have brought along many new features and possibly better performance in the same package. However, TSMC cancelled the process so Cayman had to resort to the more mature 40nm process, sacrificing many of the new features promised.

The biggest change to the architecture is the use of the VLIW4 design instead of the VLIW5 design used since DX9 graphics cards were 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.

Cayman: VLIW4, 24 SIMD clusters, 96 texture units
Cypress: VLIW5, 20 SIMD clusters, 80 texture units

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, Cayman comes in two variants as found on the HD6950 and HD6970. The key difference is that the HD6950 has 22 SIMD clusters instead of 24 on the HD6970, leading to fewer texture units (88 vs. 96) and fewer stream processors (1408 vs. 1536). The GPU boasts an impressive 2.64 billion transistors on a die size 389mm squared. For reference, the mainstream Barts core sports 1.7 billion transistors on a 255mm squared package. A 256-bit GDDR5 memory bus is still supported but this time 2GB of VRAM is provided to compete with Nvidia’s offerings.

Product Specifications
Graphics Engine: AMD HD6950
Model: ASUS EAH6950 DCII 2DI4S/2GD5
Bus Standard: PCI Express x16 2.1 (Compatible with 1.1)
Memory Size (MB): 2048 GDDR5
Memory Interface: 256-bit
Core Clock Speed (MHz): 810
Stream Processors: 1408
Shader Clock (MHz): 810
Memory Clock Speed (MHz): 5000

3D API: Direct X 11 & OpenGL 4.0
DVI Output: 2 (DVI-I & 1 DVI-D)
HDMI: 1 (HDMI 1.4a w/audio via DVI to HDMI x1(8 channel LPCM & bitstream))
DisplayPort: 4 DPs 1.2
HDCP Support: Yes
DVI Output (Max Resolution): 2560 x 1600
D-Sub Output: 2048×1536
Crossfire Support: Yes
Card Dimension (mm): 292 x 125 (Triple slot)

Features

Get Immersed with AMD Eyefinity Technology
•Enable ultra-high resolution multi-monitor gaming with 2GB of high speed GDDR5 memory.
•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 up to 4 simultaneous displays.
•Get the freedom and flexibility to upgrade. This modular solution enables you to add additional displays.
•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
•New and advanced architecture featuring full DirectX® 11 support and scalable geometry processing.
•Featuring a new and advanced architecture with scalable geometry processing, the AMD Radeon HD™ 6900 Series is purpose-built to dominate your games.
•Maximum efficiency & performance. AMD PowerTune technology puts exceptionally intelligent power management under your control.
•Raise the bar for beautifully smooth image quality with Enhanced Quality Anti-Aliasing (EQAA).
•Dual advanced programmable tessellation engines for twice the geometry processing performance of previous generations.
•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
•Unleash the most demanding applications with AMD Accelerated Parallel Processing (APP) technology.
•Supports double precision floating point arithmetic to handle computationally intense workloads.
•Smooth visual quality with AMD EyeSpeed visual acceleration technology.
•Experience Blu-ray 3D as it was intended with AMD HD3D technology.
•Take advantage of AMD Radeon™ HD 6900 Series graphics’ Dolby TrueHD and 3D HDTV support.

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
Gets up to 1.8X of a graphics performance boost in dual mode.

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

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

ASUS Exclusive Innovations

•DirectCU II: Based on ASUS DirectCU architecture, which uses copper heat pipes in direct contact with the GPU to speed up heat dissipation for over 20% cooler performance, DirectCU II takes cooling further with twin 100mm fans for 600% airflow.

•Super Allow Power: Super Alloy Power technology uses special alloy formula in critical power delivery components for a 15% performance boost, 35C cooler operation and 2.5 times longer lifespan.

•SIX monitors output for the win! Exclusive 6 monitors output via 2 DVI & 4 DisplayPort Output.

•Voltage Tweak: Full throttle overclocking with exclusive ASUS Voltage Tweak via Smart Doctor – boosting 50% more speed, performance and satisfaction! (The quoted figure of 50% is based on the increased headroom as opposed to actual 50% better performance)

•Overclocked: Factory overclocked to perform at 810MHz, 10MHzhigher than stock performance, resulting in higher frame rates in games.

•ASUS Smart Doctor: Intelligent system monitoring for efficient overclocking with an intuitive slide bar

•ASUS Gamer OSD: Real-time overclocking, benchmarking and video capturing in any PC game!

•Splendid Video Intelligence Technology: Optimizes colours in various entertainment scenarios with five special modes — standard, game, scenery, night view and theatre.

Packaging and Content

The front of the box

The ASUS packaging is no stranger to us here and the one used for their HD6950 is exactly the same as that seen with their HD6970, both in terms of size and design. ASUS have kept to their traditional red and black themed box, depicting a rampaging horseman to symbolise their dominance and power. The box highlights some the card’s key features, most notable the DirectCU II cooler which is printed in bold at the bottom and illustrated below the ASUS logo. The claim is that it is 20% cooler than the reference vapour chamber coolers, a significant feat if true. The red background denotes that the graphics card is of course from AMD.

The features

Taking a closer look at the illustrated features, we can see that the HD6950 comes pre-overclocked at 810MHz, 10MHz above the default 800MHz speed. While not a significant boost, it’s other features more than make up for it. The card boasts 2GB of on-board GDDR5 memory for exceptional memory bandwidth. Moreover, it is also illustrated that the ASUS board employs Super Allow Power, an exclusive feature to their latest line of DirectCU II graphics cards. Impressively, the HD6950 also has a total of 6 outputs, allowing it to support up to 6 screens in Eyefinity configuration. Typically, 6 monitor output has always been limited to special edition Eyefinity cards or other custom card designs but none have the sheer number of DisplayPort connectors as the new ASUS cards. And just above those icons is a teaser picture of the DirectCU II cooler.

The back of the box

The back of the box is more informative and covers some of the card’s key characteristics is greater depth. At the top, the features are listed in 11 languages whilst below that are illustrations of Eyefinity in action and the DirectCU II’s unique features, as well a short description of their benefits. Additionally there is an illustration of the different display connectors that can be found on the card’s I/O panel. There is no mention of the voltage tweak feature but this comes supported as standard through the SmartDoctor application.

The features in detail

Looking closer, we can see that ASUS expect the dual fan design of the DirectCU II cooler to run 20% cooler, although how this is quantified is a mystery. The “Super Alloy Power” refers to new on-board components able to run cooler in order to maintain longer lifespan. These help the power circuitry as we will see later on.

Opening the box

Inside the main box, we are greeted with another which upon opening reveals a paper wallet within a foam encasing. The wallet holds the driver disc and installation manual, and when removed from the middle foam cut-out exposes the graphics card nicely wrapped in an anti-static bag.

Inside the box

Beneath the top foam encasing is the beast of the graphics card and the additional accessories in a small separate cut-out to the side. The graphics card is well secured and packaged and should be well protected during transit despite its size and weight. Overall, the packaging still retains the quality and professionalism we have always attributed to ASUS.

The bundle

Bundled alongside the HD6950 are:

– 1 x Dual Molex to 6 Pin power adapter
– 1 10CM Crossfire Bridge
– 1 x Multi-lingual quick-installation guide
– 1 x DVI to HDMI adapter
– Driver disc

The bundle is fairly standard but it can be seen that some thought was given to what was included. The DVI to HDMI adaptor ensures that users can choose between three types of connectors including DVI and DisplayPort which are supported on the I/O plate. Due to the size of the graphics card, ASUS have also included a 10cm crossfire cable rather than a regular 7.3cm one to ensure a wide enough gap to install a second card. My only complaint is that the dual Molex to 6 pin power adapter should have been replaced with a dual 6 pin to 8 pin adapter, given the 8 pin PCIe connector on the card instead of the usual second 6 pin connector.

Closer Look

The graphics card

If I had to choose one word to describe the HD6950 DirectCU II, it would be “monstrous”. The triple slotted card makes use of a cooler than spans 2.5 slots. The graphics card makes use of a custom PCB design and a custom dual fan cooler to match. The outer shroud is of metallic construct, giving the card a very solid and robust feel. It has a very distinct shape with vents on the side to dissipate the air that is pushed down towards the GPU. The rounded edges makes for a very attractive finish and the red stripe going through the middle is reminiscent of the livery used on their reference boards. The DirectCU II logo has been thoughtfully place in the cooler for an added finishing touch.

The back of the card

The back of the card has been left bare. No backplate is installed but this isn’t wholly necessary when all the components that require cooling are on the other side of the PCB. The heatsink is secured only by 4 spring loaded screws and to remove the cooler; those 4 screws have to be undone. From this angle, we can see that the shroud extends further than the PCB making the whole card 29.2cm in length so it is important to ensure that it will fit inside cases.

The DirectCU II Cooler

The DirectCU II cooler makes use of two 100mm for a claimed 600% increase in airflow. This is coincidently what ASUS promised their ARES HD6970 would bring so it is clear that their technological innovations has seeped through to more mainstream cards. The fans are designed to blow ait towards the components rather than blowing air towards the exhaust ports at the back. Nonetheless, the design promises much better thermal performance. At the back of the shroud, the curved down panel protects the heatsink and makes for an overall better finish.

The CrossFire connectors

The two CrossFire connectors on the side provide support for up to 4 graphics cards to be used simultaneously in CrossFireX. However the sheer size means that most motherboards will be limited to either 2 way or 3 way-CrossFire. A support bar has been installed on the side of the PCB to avoid the card flexing under the weight of the heatsink.

The DVI switch

This is where it gets interesting. Reference HD6950s have a switch on the side that allows users to switch between a protected factory BIOS and a second BIOS. The HD6950’s ability to unlock to a full HD6970 has made it common place for buyers to opt for the cheaper SKU and simply unlocking to the latter. ASUS have kept the switch on their HD6950 but its purpose is completely different. The switch merely switches the dual link DVI port on the I/O panel to a Single Link port and “unlocks” one of the four DisplayPorts linked to it.

Illustration of switch functionality

The diagram shows a clearer image of the switch turning the Dual Link DVI into a Single Link DVI & DisplayPort connector by sharing the bandwidth. This makes the switch an ideal addition for those interested in multi-monitor usage. The obvious disadvantage is that users can’t switch to a second BIOS for potential unlocking. ~~Given that the board is custom to ASUS and doesn’t share components with the reference designed HD6970, it is impossible to unlock the card anyway~~.

EDIT: This card CAN be unlocked by simply unlocking the shaders using TechpowerUP’s Radeon Bios Editor (RBE). Although it is possible to simply flash the ASUS HD6970 DirectCUII BIOS, the latter features slightly different memory modules and therefore a straight flash isn’t advisable. Using RBE instead allows to retain all the HD6950 attributes and simply unlocks the extra shaders. Note that only earlier versions of this card support unlocking due to AMD’s decision to start laser cutting the extra shaders. This particular sample was unlocked sucessfully as a result.

The I/O Panel

Going to a triple slot design has allowed ASUS to go wild on the number of connectors on the I/O panel. At the base are 4 DisplayPort connectors and above those are 2 DVI ports. The DVI port to the left is a Single Link DVI-I port whereas the one to the left is a Dual Link DVI-D port, as indicated by the engravings to the side. The DVI-I port can be used with a VGA adaptor for legacy devices that are limited to analog signals. The DVI-D port shares bandwidth with the DisplayPort below it and thus the switch allows users to configure the two as illustrated above. The reference HD6970 only uses mini-DisplayPorts but has an extra HDMI port. The DisplayPorts support the latest 1.2 standard. 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 an MST hub. If a hub isn’t available and daisy chaining not feasible, the 6 ports can still support up to 6 displays in Eyefinity as illustrated at the back of the box. The higher bandwidth of the DP is also relied on for AMD’s new 3D stereoscopy initiative.

The PCIe power connectors

Unlike regular HD6950s, the ASUS card has one 6 pin and one 8 pin PCIe power connector telling us that the card has been designed to be overclocked and not be limited by power draw. It also means that the maximum TDP is raised to 250W before PowerTune kicks in to throttle the card. These are conveniently situated on the side rather than at the end to ensure that the cables do not get in the way of HDD cages or other components.

The reference HD6970 VS the ASUS DirectCU II HD6950

Next to the already lengthy reference HD6970, the DirectCU II HD6950 is an absolute monster spanning 29.2cm, 1.8cm longer than the former card. Not all cases will support this card so ensure compatibility first before buying.

Closer Look (Continued)

The shroud removed

The whole card can be dismantled quite easily. Simply removing 6 screws allows us to remove the shroud and reveal the shape of the heatsink below it. The heatsink spans the length of the graphics card giving it plenty of surface area for heat dissipation. The fans are then placed above pushing down air towards the GPU. ASUS have moved away from the vapour chamber cooling solution so it will be interesting to see if the heat pipe design will reign superior or not.

Beneath the shroud

Underneath the shroud, the fans are mounted to a scaffold like structure. The metal bracket provides additional support and allows the shroud to be secured to the heatsink. Each fan has a 4 pin connector for PWM functionality and a y-splitter has been employed to keep everything tidy. The 9 bladed 100mm fans should be more than enough to keep the card cooler compared to the single fan design of the reference card.

The heatsink

The heatsink is composed of two horizontally mounted fin arrays. The first is merely an aluminium block installed on top of the GPU for quick dissipation of heat across 29 fins. The second part that overlies the memory and power circuitry is connected by three heat pipes and is made up of 48 densely packed aluminium fins. The three copper heat pipes are in direct contact with the GPU so efficiency can be maintained, hence the DirectCU moniker.

The bare PCB

The layout of the PCB is very similar to the reference board in terms of where the components are positioned but otherwise ASUS have gone for a completely custom design. The GPU sits in the middle surrounded by eight memory modules and to the right is the power circuitry.

The Cayman GPU

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 memory modules

The memory modules are once again GDDR5 chips sourced from Hynix rather than Samsung. The H5GQ 2H24MFR T2C 049A 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. These are slightly updated versions of the chips used on the regular HD6950s which are the “039A” versions.

The GPU power circuitry

The power circuitry features a 7 phase power design for the GPU alone and makes use of ASUS’s new Super Alloy technology. They have been built to ensure longer lifespan and cooler operation. Each choke has the “Super Alloy Power” logo imprinted on top. The two missing chokes indicate that the HD6970 has an extra 2 phase power. The MOSFETs are cooled by their own heatsinks.

The memory VRM circuitry

The memory boasts its own 2 phase VRM circuitry for more stable overclocking and operation.

The SHE voltage controller

Instead of the Volterra VT1556MF voltage controller found on reference boards, ASUS have opted for an SHE based one. Voltage tweaking is thus only supported through the SmartDoctor software. Because of those differences, there is no chance of unlocking the card to a HD6970 BIOS.

The card installed

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:

ASUS HD6950 2GB DirectCU II @ 810/5000MHz & 984/5480MHz Overclocked – ATI Catalyst 11.2a

Inno3D GTX570 1280MB @ 732/3800MHz, 800/4000 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 10.12a (8.790.6.2)
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

The Software Bundle & Power Monitoring

The driver CD includes the user manual, drivers and ASUS utilities, presenting them in an attractive bubbly user interface. The latest 11.2a drivers can be downloaded here.

The ASUS SmartDoctor tool is an overclocking utility that has the unique capability of allowing users to increase the GPU core voltage. The user interface isn’t as sophisticated as MSI’s Afterburner application but keeping it simple is not always a disadvantage. At the bottom are three slider bars where users can select the VCore and clock speeds. The maximum limit for the voltage is 1.5V while the clock speed is limited to 1780/11000MHz (limited is probably not the right word…), plenty of headroom for this card. On the main screen, the application displays the temperature or selecting the fan tab will show you the fan speed. Going into the settings, it’s possible to create a fan profile based on temperatures.

Here, we can see how easy it is to overclock. Simply use the sliders to set the desired clocks and it’s good to go. Of course, this doesn’t imply that all clock speeds will work and users will still have to go through the usual steps of testing for stability.

The latest drivers bundles the new Catalyst Control Centre interface which is on the whole a more intuitive experience. Each section to the right has been neatly arranged for users to customise a range of options. The overdrive tab is largely unchanged in functionality. Overdrive gives uses the ability to overclock their graphics card and monitor temperatures and fan speed. Although not as thorough as MSI Afterburner, it is still a very useful tool. The new feature, shown above as Power Control Settings, is AMD PowerTune.

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, the PowerTune Maximum Power is set to 200W whilst on the HD6970, it is set to 250W. 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 main situation where it PowerTune would kick in is under heavy loads from programs such as the stress test applications mentioned above. This particular HD6950 by ASUS most likely has its maximum TDP set to 250W to make better use of the power connectors on-board.

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. 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 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. This gives overclockers additional headroom 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 you can imagine, overclocking was an absolute breeze on this card. The main obstacle is the lack of BIOS switch and possibility for unlocking so for the HD6950 to compete against even the reference cards, it will have to be able to outperform a HD6970 once overclocked. The ASUS HD6950 DirectCU II comes pre-overclocked at 810/5000MHz, 10MHz more than the reference cards on the core. Despite the cooler, ASUS did not provide a healthier overclock leaving users the joy of overclocking. The card operates at 1.0V at idle when it clocks down to 450/5000MHz in dual screen mode and 175/300MHz with just one monitor. Under load, it operates at 1.1V.

Because of the custom design of the card, SmartDoctor is the only application capable of tweaking the voltages using the SHE controller. Initially, the application limited the maximum core clock to 950MHz but the headroom limit can be removed in the settings. In the end a final clock speed of 984/5480MHz was reached with a voltage of 1.25V on the core. This represents a 24% boost on the core speed and a 10% increase in memory clocks. The clocks were tested to be stable by undergoing gaming sessions and the benchmark suite without problems. In this case, voltage tweaking also has its disadvantages. As expected, increasing the voltage also raises power consumption so improved headroom is inhibited by PowerTune’s maximum TDP limit. Getting optimal performance without TDP reducing the core speed dynamically requires a fine balance of lower voltages and stable clock speeds. The power control setting was set to 20% throughout testing. Thankfully, the improved power circuitry helps in reducing power consumption and the maximum TDP has been raised to match the HD6970s. When overclocked, the core idles at 500MHz instead of 400MHz.

The overclock provides a significant boost to the HD6950’s specification, increasing the fill rates and shader operation by 24%. Similarly, the memory bandwidth is also increased by 10% making it close to that of the HD6970’s. The overclocked HD6950 manages to surpass the specifications of the HD6970 despite its 1408 stream processors.

In real world performance, the 24% overclock resulted in an average 13.9% boost, nowhere as linear as what we would expect but nonetheless free performance. It is possible that PowerTune limited the scalability of the overclock. Still this overclock is enough to match the performance of a stock clock HD6970.

Temperature & Noise

The highlight of the cooler is without a doubt the cooler which not only dominates its look but also the card’s appeal. The temperature results do the premium feel of the card justice with some of the lowest temperatures we have recorded. At stock speed, the temperature delta under load was a mere 49C, lower than everything bar the DirectCU based HD5850. More impressively, it did so at a measly 25% fan speed which was inaudible as you would expect. At idle, the fan operated at 13%.

Even when overclocked, the load temperature only increased by 4C for a delta of 53C, 14C lower than the reference cooler. Under load, the fan only ramped up to a maximum 28% speed to compensate for the higher heat output. At idle, the fan speed only went up by 1% compared to previously. To make sure that the fan was indeed alive, I increased the fan speed to see at which point it became audible. At 30%, a gentle hum could be heard and increasing to 40% still yielded somewhat quiet noise levels. It wasn’t till the fans reached 55% fan speed that it became intrusive but again this was easily drowned by games. Even at 100%, the fans never reached the blow dryer noise levels of the reference vapour chamber cooler. Kudos to ASUS!

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.

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

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.

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.

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.

Strangely, the ASUS HD6950, despite its 10MHz overclock, couldn’t keep up with the reference HD6950 from HIS. This behaviour was observed throughout the entire benchmark suite and using every known driver since the release of the Cayman GPU made no impact in improving its performance. As a result, it drops behind the standard HD6950 by 1.1%. Compared to other cards, the ASUS HD6950 represents a marginal upgrade from the Cypress based HD5870. It also ends up 12% behind the HD6970.

The truth is that the card was built for overclocking so that’s what we will focus on. Once overclocked, it leaps ahead of the reference card and closes the gap even on the overclocked HD6970. For reference, the latter was clocked to 949MHz on the core, not far behind the 984MHz achieved on the ASUS card. The difference between the two was a mere 3% showing that even though the DirectCU II card cannot be unlocked, it can still match HD6970 performance level. In fact, the overclocked ASUS HD6950 did just that and managed to draw level with a stock clocked HD6970. It can be argued that a reference card will do so more easily through unlocking and still have further headroom for overclocking but they would lack the thermal benefits of the DirectCU II cooler. The overclocked ASUS card is no match to the overclocked GTX480 and GTX570 in this case which are priced similarly.

Power Consumption

Tessellation

DX 10

DX 11 Tessellation off

DX 11 Tessellation off – wireframe mode

DX 11 Tessellation on

DX 11 Tessellation on – wireframe mode

Let’s focus on a few characteristics of tessellation in the first image. Firstly, when we compare the wireframe mode, it is clear that tessellation, triangular in this case, is adding a lot more features and details, which may at first not be recognisable. The surfaces are divided in many more triangles, allowing the objects to replicate more complex structures. The ground for example is one of the features that benefits from it. To make it as efficient as possible, tessellation becomes a function of distance, generating more polygons closer to the viewer.

Now let’s look at the application of this. If we gaze at the rock pillar closest to us, we can immediately notice that with tessellation, they are not just mere square blocks but instead have irregular surfaces, more representative of a natural rock. Now, let’s move on to the stairs, which again is a notable improvement on past rendering methods. Rather than being flat, they have depth, giving the impression of real steps as opposed to a slide. The same applies to the cobbled road although the compressed/downsized pictures make it hard to judge. The last thing I’ll point out are the tiled roofs. With tessellation, the individual tiles form a more complex/realistic shape instead of appearing flat with repeated textures. You’ll have to take my word for it if you don’t notice them or try the demo for yourself!

Conclusion

ASUS have succeeded in what they set out to achieve. They have created a card with tremendous cooling potential and overclocking headroom that transforms AMD’s HD6950 from being a mediocre overclocker to one of the best in this regard. Their voltage tweaking utility proves invaluable in unlocking the full potential of the HD6950 GPU, although it can be argued that to truly unlock its potential one could unlock all its stream processors. Unfortunately, this is where ASUS lets us down. In customising their card for durability, low operating temperatures and stability, they sacrificed the ability for the card to be unlocked to a HD6970. Nonetheless, ASUS makes up for that by allowing the card to overclock to an impressive 984/5484MHz, a 24/10% overclock on the core and memory respectively that enables their HD6950 to match HD6970 levels of performance. The DirectCU II cooler is the highlight of the card and does an excellent job at taming the temperatures while still remaining near silent at all times. It does come at the cost of an extra slot and length but it demonstrates some of the innovations that the exclusive ARES card brought to the world. If ASUS could still retain similar efficiency in a smaller package, they would be on to a winner. Sometimes, a fine balance between performance and size has to be reached rather than compromising one for the other.

Performance wise, the ASUS HD6950 had some problem keeping up with the reference card despite its 10MHz overclock. The problem wasn’t driver related but it was a very marginal difference. Once overclocked, it managed to leap ahead of the overclocked reference card by 3%. The problem was that the overclock didn’t generate the same linear scaling the reference card demonstrated. It is likely to be due to PowerTune throttling the card as a result of the maximum TDP being exceeded. The overclocked results were enough to close the gap between itself and an overclocked HD6970 and more importantly the ASUS card managed to beat a stock clocked HD6970. On the whole, the card’s performance was very good and the 2GB framebuffer coped with high resolution gaming and high levels of Anti-Aliasing very well. In popular games such as Crysis Warhead and Battlefield Bad Company 2, the HD6950 presents very good value for money, generating up to 85% of the GTX580’s performance at a fraction of the price even after overclocking is taken into account.

Currently, the DirectCU II HD6950 is priced at around £250, putting it in a very difficult position to evaluate. It lies in the same territory as the cheapest reference HD6970s, GTX570s and GTX480s which are superior cards in terms or performance out of the box. The ASUS card offers much better cooling and favourable noise levels but whether this is enough to justify its premium is another question. The cheapest HD6950s are available at £200-£215 so ASUS are asking for a 20% premium above the standard card. In my opinion the card doesn’t warrant such a price hike, especially when the standard card isn’t significantly louder and has the potential to be unlocked to a HD6970s. Even disregarding this feature for people not willing to flash their graphics cards, the standard HD6950 still offers slightly better value for money. To remain competitive, the ASUS HD6950 DirectCU II will have to be priced £230 or less.

Those looking for the ultimate in cooling and one of the best overclocking cards we’ve had, this card is definitely worth considering. The HD6950 may not be the ideal card to demonstrate the benefits of the superior power circuitry and DirectCU II cooling solution (the reference AMD design is already very good), it holds promise for other cards such as the HD6970, GTX570 and GTX580. Being the best overclocking HD6950 on the market is certainly no easy feat and ASUS can proudly receive the title.

Pros
+Good performance
+Improved tessellation and AA performance
+Efficient and low power consumption
+Extremely cool and quiet operation
+Eyefinity support
+Very Well packaged
+Very good build quality
+Aesthetically pleasing
+Excellent overclocking headroom
+Vast selection of connectivity
+Voltage tweaking support
+Innovative and durable

Cons
-Stock performance somewhat lacking
–~~No unlocking potential~~

Early revisions of the card can be shader unlocked successfully

-Size
-Price

The ASUS DirectCU II HD6950 deserves the Vortez Silver Award.