Cooler Master is a household name when it comes to cases and CPU coolers, but the company has branched out in some other directions as well. Our today’s review features the GX 750W, the latest PSU from CoolerMaster’s GX series of PSUs aimed at gamers (GX stands for Gamer Extreme).
As the name suggests, the GX 750W packs 750W of power and comes with 80 Plus certificate, for which the PSU is required to deliver over 80% efficiency under 20%, 50% and 100% loads. The PSU is also nicely priced at about €80, which means that it’s aimed at higher mid-range and gamers.
Apart from the GX 750W, Cooler Master’s GX series features two more PSUs – GX 650W and GX 550W. The fact that all these pack a powerful single +12V rail (60A on GX 750W) further prove that these PSUs are made with some serious gaming in mind.
Our sample’s model number is RS-750-ACAA-E3.
• Type: Intel ATX 12V V2.31 & SSI EPS 12V V2.92
• Input Voltage: 90~264V (Auto Range)
• Input Frequency Range: 47Hz ~ 63Hz
• Fan: Super Silent 120mm Fan
• Power Good Signal: 100 ~ 500ms
• Hold Up Time: > 17ms
• Efficiency: 85% Typically
• MTBF: >100,000Hours
• Protection: OVP* / UVP* / OPP* / OTP / SCP*
• Dimension: 150 × 140 × 86mm (5.9 x 5.5 x 3.4 inch)
• Operation Temperature: 0~40℃(Nominal Input Voltage)
• Regulatory TUV / CE / UL / FCC / BSMI / GOST / C-tick / CCC / KCC
• Certification 80 Plus /SLI
• Connector 20+4 Pin MB x1
4+4 Pin CPU 12V x 1
6+2 Pin PCI-e x4
4 Pin Peripheral x3
4 Pin Floppy x1
• 5-year hardware limited warranty
*OVP (Over Voltage Protection): OVP prevents the damaging impact of excessive output voltage by shutting down the power unit.
*UVP (Under Voltage Protection): UVP ensures a constant flow of power to keep your components at their max performance.
*OPP (Over Power Protection): OPP safeguards the power supply from any overload, preventing over exposure to extreme power conditions.
*OTP (Over Temperature Protection): OTP automatically shuts down the power supply if the system overheats. This helps protect the power supply duration from any possible damage.
*SCP (Short Circuit Protection): SCP prevents any “rush back” of voltage that may cause harm to the power supply and other components.
• Compliance with the latest Intel standard ATX 12V V 2.31
• Single +12V rail for the most demanding SLI configurations
• High efficiency design that meets 80 Plus requirements (85% typical)
• Ultra-silent operation with intelligent 120mm fan speed control
• Multiple protection design (OVP / UVP / OPP / OTP / SCP)
• High reliability (MTBF>100,000 hours)
• Double Layer EMI Filter restrains noise and injury to end-user
• Huge bulk capacitor for hold up time >17ms at full loading
• Integrating Active PFC with PWM combo controller not only make PFC higher than 0.99, but also raises efficiency
• Efficient transformer for reducing 5Vsb power loss when the system is at turn-off and sleep modes
The GX 750W’s box is pretty small but features a nice color selection and follows the Gamer Extreme design.
Full specs as well as features are listed on the back of the box whereas the sides are reserved for connector descriptions and regions this PSU is supposed to be sold in.
Within the package is the PSU, user’s manual, a plastic bag with mounting screws and the warranty card.
The GX 750W resembles most other PSUs in its class, except perhaps for the fact that it’s slightly shorter. The GX 750W measures 150 × 140 × 86mm or 5.9 x 5.5 x 3.4 inches.
That the PSU is slightly shorter is evident from the following picture where you see the GX 750W barely reaching the rubber rails in the Cooler Master 690 Advanced case. This PSU doesn’t come with modular design, but cables won’t be a problem in cases like Cooler Master 690 Advanced as the cables can be routed behind the motherboard and thus hidden.
All the cables are wrapped in protective plastic mesh and are aimed to provide anything a user might need. So, the CPU connector is 4+4 pin, PCI express connector is 6+2, etc., which enables the user to make different system setups.
The PSU features:
- Main motherboard cable with a 20/24pin connector. Length is 50cm.
- One cable with two ATX12V connectors which together form one EPS12V connector. The cable is 60cm in length.
- Four cables with 6+2 pin connector for graphics cards. The cables are 50cm long.
- Two cables, each with 4 SATA power connectors. The cable is 45cm long to the first connector; the distance between subsequent connectors is 10cm.
- One cable with SATA power connector, three standard connectors for peripheral units and one floppy connector. The cable is 45cm long to the first connector; the distance between subsequent connectors is 10cm.
The following picture shows the table on the GX 750W’s side, and it confirms the PSU is 750W. We only have one +12V rail with 60A which packs enough juice for stronger graphics cards. As you can see, the GX 750W offers four graphics card connectors, which pretty much means it will easily drive more power-hungry graphics cards.
The GX 750W is cooled by an internally controlled 120mm fan. Fan speed is altered based on actual temperatures within the PSU. The specs say that the fan is quiet and we can confirm that.
Noise is an important point that often plays a key role in choosing a PSU, but the same can be said for virtually any other PC component.
The back of the PSU has a mesh surface that improves airflow.
The following photo shows the GX 750W’s internals.
Unfortunately, we don’t have the equipment to put Cooler Master’s 80 Plus Silver Certificate to the test, so we opted on practical tests that will show whether Cooler Master’s new PSU has what it takes to drive a powerful gaming PC.
Our test is divided in two parts:
We first tested the GX 750W using a slightly older system based on MSI’s P45D3 Platinum, overclocked Intel Core 2 QX9770 Extreme Edition at 3.6GHz and Radeon HD 4870 X2. The rig ran on two hard disks, 2GB of OCZ’s DDR3-1600 Platinum memory, DVD writer, Hyper 212 Plus cooling and few fans. The first test shows that the GX 750W won’t break a sweat under a 500W and will run silent.
The second part of our testing is reserved for top performance and efficiency – meaning throwing pretty much everything we got at it. We ended up using EVGA’s high end X58 Classified 4-Way SLI, Intel’s Core i7 Extreme 965 overclocked to 4GHz and 6GB of Corsair’s Dominator 12800 memory. Since the motherboard is pretty large and couldn’t fit into the 960 II case (or any other case we have, for that matter) we performed our testing on an open platform using Cooler Master’s TestBench v1.0.
For our testing we used MSI’s N260 GTX and currently the fastest graphics card - the HD 5970. After we measured total system consumption in idle and active modes with both aforementioned graphics cards, we redid the same tests with XFX’s 850W Black Edition.
In the following tables you’ll see the difference in consumption between the two PSUs. The GX 750W is powerful enough to provide over 600W with no trouble, but we see that a power-hungry system such as ours won’t consider the GX 750W quite ideal. XFX’s 850W PSU is pricier, but more efficient as well and might save you a few euro on your yearly power bill.
Note that the comparison is probably not fair on the GX 750W, as it ran under a load of around 80%, whereas the stronger 850W Black Edition considers that same load as only about 70%. If we look at the total system consumption, the difference is about 3.1% or 19W. The same test system with N260 GTX rates the difference at 2.5% or 11W. Although results obviously prefer the XFX 850W Black Edition in systems that consume more, note that the price difference is around €50. This means that if you require below 600W for your rig, the XFX 850W might prove to be an overkill and probably financially unsound as any potential cash saving cash on your power bill saving won’t really pay off anytime soon to justify such a purchase.
Idle mode operation is another story altogether as the GX 750W shows that we’re talking about a quality PSU here – the difference is virtually nonexistent.
Cooler Master Gamer Extreme series was announced only recently and the series features three PSUs: GX550W, GX650W and our today’s sample - the GX 750W. Cooler Master is keen on establishing its name on the PSU market and we firmly believe they’ll manage to do that with the new Gamer Extreme series and the upcoming Gold Series (we’ve mentioned it here).
Our GX 750W has proven to pack enough juice to drive some serious rigs and it’s available at about €85 here or $114.99 here. The design is pretty compact – it’s slightly shorter than most PSUs in its class so you won’t have problems with fitting it in smaller cases. The fan is quiet which is pretty important.
We’re talking about a single +12V (60A) rail PSU with plenty of connectors but no modular design. Cooler Master provides four 6+2 pin power connectors for graphics cards, meaning that it will easily support two graphics cards with heftier power requirements.
Our practical testing shows that the GX 750W packs enough punch and will provide power for systems that draw above 600W (most gaming machines draw below 600W), but it’s still more efficient in systems with consumption below 600W. The PSU is stable, quiet and perhaps most importantly - nicely priced. So, with that in mind – what’s there not to recommend?