Cooler Master GX 550W Power Supply Review

Last month Cooler Master released a new series of power supply units targeted at the gamer. We take a look at the 550W variant.

Product on Review: Cooler Master GX 550W
Manufacturer: Cooler Master
Street Price: Approx £60

Cooler Master announced the GX series at the end of January and was showcasing these products to the world at CeBIT just last week. The GX series stand for Gamer Xtreme and comes in three power ratings – 550W, 650W and 750W hoping to target mid-range to high-end gaming systems by offering a single +12V rail designed to provide sufficient power to dual graphics card systems such as CrossFireX and SLi. The 750W version even comes with four PCIe connectors.

Up to 85% efficiency is available with all of the GX units being certified with 80 plus rating – good news if you are looking for a power supply unit capable of handling multiple graphics cards.

Cooler Master have the following to say about the GX series.

The Cooler Master GX series power supplies stand for Gamer Xtreme, the evolved version of extreme power plus. With up to 60 amps on a single rail, there is enough power to start up a car. Imagine what it can do for your system. With so much power at your disposal, Cooler Master ensures the most stringent safety standards are met. The extended 5-year warranty is included to give you further piece of mind.

I’ll be looking at the 550W variant today which is the smallest of the three units in terms of overall wattage but hopefully it will pack a punch. Over the page we will begin.

• Compliance with the latest Intel standard ATX 12V V 2.31
• Single 12V rail for most demanding SLI configurations
• High efficiency design that meets 80plus requirements (85% typical)
• Ultra-silent operation with intelligent 120mm fan speed control
• Multiple protection design
• High reliability
• Huge bulk capacitor for hold time up >17ms at full loading
• Integrated Active PFC with PWM
• Efficient transformer
• Five year warranty

GX 550W

With the technical run down out of the way we can take a good look at the unit Cooler Master have sent. As already mentioned we have the 550W variant identified from the other versions by its strong display of green artistry. Our box immediately shouts ‘gamer’ by its distinctive typography and graphics. On the side we get a glimpse of what cables come with our Cooler Master GX 550W.

• 1x 20+4Pin Motherboard Connector
• 1x 4+4Pin CPU +12V Connector
• 2x 6+2Pin PCI-e Connector
• 6x SATA Connector
• 3x 4Pin Peripheral Connector
• 1x 4Pin Floppy Connector

So all the above connectors are what you would expect from a unit of similar calibre. Opening the box up we see the full range of contents included. Here is the list.

• Cooler Master GX 550W
• Power cable
• Installation screws
• Manual
• Warranty card

Taking a closer look at the unit itself, as with the typical power supply unit one side has the power ratings. These ratings look solid, what you may notice fairly quickly though is that for the 12V+ line there is just a single rail rather than being distributed amongst multiple rails CM have decided to give the GX a single 12V+ that is pretty strong. 44A and a maximum of 528W is quite impressive. This will be able to take pretty much anything I throw at it. Another thing to note is the dual 5V rails. Usually our units would have just the one 5V rail, some extra power for multiple HDD/DVD drives.

The GX unit comes with an ‘ultra silent’ 120mm speed controlled fan. A little later we will see just how quiet this is. Having the GX cables stretched out shows the rather lengthy coverage they give you. There should be no problems at all with having this in a top or bottom seated configuration inside the case. What I like especially about this unit is that CM have chosen to braid the cables in the sleeve from within the actual unit rather than like other manufacturers – begin sleeving the cables an inch or two outside which makes it looks messy and doesn’t really assist with that all important cable management which is the whole reason you want a sleeved unit.

Below is a nicely arranged diagram for you to check out the various internal components inside the GX. Testament to the features that Cooler Master refer to in their specification notes, they don’t just talk the talk – justified engineering right here.

GX 550W Continued

Below you can see the length of the cables coming from the GX unit. Suitable for most of the cases in the market today, although putting this into a full tower case may be a little bit of a stretch. But I’m only talking about the tallest of cases here.

Performance

Our testing methodology for testing Power Supply Units is limited to the multi-meter to show each rails performance due to us not having access to an ATE load tester. Although this does constrain us slightly we can still ascertain how strong those rails are and give the unit a good assessment when we feature it in one of our builds. The way the testing will run is simple, voltages will be observed at idle wattage and then the system will be loaded using OCCT and again the wattage/voltages will be monitored. This should give us a good indication of how the GX will perform under gaming stresses and beyond. The OCCT PSU load test is very severe indeed and a good representation of testing.

Test System
CPU: Intel Core 2 Duo E2160 (3.5GHz)
Motherboard: ASUS P5KC
RAM: 2GB OCZ Platinum DDR2
GPU: MSI 8800GTX
PSU: Cooler Master GX 550W

The above results do look good, the minor rails hardly budge at all under the most intense of usage. 0.02 on the 3.3V rail and just 0.03 on the 5V rail isn’t bad going at all. When we come to the major rail however the voltage different is quite a lot bigger. 1V to be exact which may not sound massive but I would have expected it to be a little stronger. With the voltages on the PSU we are wanting to find the closest values to the actual rail. So for example we want to see values that are as close to 12V on the 12V rail as possible.

Don’t get me wrong this is a powerful unit and it does offer some great performance, but compared to other units of similar rating it falls behind slightly.

Noise
When you’re on the hunt for a PSU not only do you want something strong and stable but you want something that will operate with as little noise output as possible (unless you are strange and like humming noises?!). With the Cooler Master GX there are absolutely no worries in this department, there statement in the features specification ‘Ultra-silent operation with intelligent 120mm fan speed control’ holds true to its meaning, its barely audible both under idle and loaded states. The fan RPM did increase when I pushed it on with OCCT but noticing this by means of noise isn’t evident and this is great news since there are at least 5 fans in most systems.

Conclusion

The power supply unit is one of the most important aspects of any system and even more so to the owner of a gaming, enthusiast or system builder. Buying a substandard \’no-frills\’ PSU will only hold you back and could even mean having to recover fried components should it blow (and trust me they do). With the GX from Cooler Master you can rest assured you have invested in a quality bit of kit. 5 years warranty should justify this.

It may be in the budget range of units but it boasts some fine engineering. It had no trouble powering the moderate gaming system I installed it in, and under 100% load quietly operated with no disturbances.

Others have criticized its inability to harness a modular design, but we have to remember that this is in a different genre and for this its priced differently. Cool Master have other units in other ranges such as the Silent Pro (and now Silent Pro Gold) which are modular and thus these units are priced and aimed at a different set of buyers too. I believe the GX 550W which has an estimated price of £60 is extremely good value for money when you look at the other contenders in this bracket. Not a lot of them offer you a 5 year warranty.

For a bit of fun check this out: http://www.youtube.com/watch?v=6eZ2vctGCaU

The Cooler Master GX 550W has a lot going for it and if you are in the market for buying a new PSU then I would advise looking at the GX series. For the above reasons this unit receives the Silver award.

Pros

+ Affordable
+ Plenty of power on the 12V rail
+ 5 year warranty
+ Great performance

Cons

– Voltages fluctuated 1V on the 12V when testing
– Cable ties would have been a nice addition