EVGA GQ Series 750W PSU Review

Efficiency, Temperature And Noise

Efficiency

Our efficiency testing procedure is detailed here.

Using the results from the previous page, we plotted a chart showing the 750 GQ's efficiency at low loads, and loads from 10 to 110 percent of the PSU's maximum-rated capacity.

Under light loads, the 750 GQ manages to match the higher-priced G2 model's performance; under normal loads, it trails a bit. Overall though, the GQ achieves good efficiency, especially if we take into account its affordable price.

Efficiency At Low Loads

In the following tests, we measure the efficiency of EVGA's 750 GQ at loads significantly lower than 10 percent of its maximum capacity (the lowest load the 80 Plus standard measures). The loads we dialed were 20, 40, 60 and 80W. This is important for representing when a PC is idle, with power-saving features turned on.

Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan Speed (RPM)Fan Noise (dB[A])PF/AC Volts
11.202A0.501A0.482A0.195A19.6672.68%00 dB(A)0.889
12.126V4.983V3.304V5.099V27.05115.0V
22.435A0.999A0.999A0.391A39.7882.70%00 dB(A)0.925
12.124V4.977V3.299V5.093V48.10115.0V
33.664A1.496A1.515A5.089A59.8186.26%00 dB(A)0.945
12.117V4.973V3.294V5.089V69.34115.0V
44.891A2.013A2.003A0.785A79.8287.90%00 dB(A)0.952
12.111V4.970V3.291V5.084V90.81115.0V

Under light loads, the PSU's fan doesn't spin and efficiency is pretty high (even down to 20W). Apparently the ACRF topology in this unit has low power losses, allowing for increased efficiency without the use of exotic and expensive parts.

5VSB Efficiency

The ATX specification states that 5VSB standby supply efficiency should be as high as possible, recommending 50 percent or higher efficiency with 100mA of load, 60 percent or higher with 250mA of load and 70 percent or higher with 1A or more of load.

We will take four measurements: one each at 100, 250 and 1000mA, and one with the full load the 5VSB rail can handle. 

Test #5VSBDC/AC (Watts)EfficiencyPF/AC Volts
10.102A0.5268.42%0.129
5.107V0.76115.1V
20.252A1.2977.25%0.230
5.105V1.67115.1V
31.002A5.1079.32%0.370
5.090V6.43115.1V
43.002A15.1779.72%0.439
5.053V19.03115.1V

The 5VSB rail registers high enough efficiency levels, although it doesn't manage to pass the 80 percent mark in any test. It does get close under full load, however. In general, the performance of this rail is pretty good since it combines tight load regulation with increased efficiency.

Power Consumption In Idle And Standby

Mode12V5V3.3V5VSBWattsPF/AC Volts
Idle12.148V4.982V3.304V5.112V7.410.708
115.1V
Standby0.150.028
115.1V

In the table above, you'll find the power consumption and voltage values of all rails (except -12V) when the PSU is idle (powered on, but without any load on its rails), and the power consumption when the PSU is in standby mode (without any load, at 5VSB).

Vampire power isn't as low as in other PSUs we have tested. Still, EVGA's 750 GQ passes the ErP Lot 6 2013 requirements with flying colors, with both 115V and 230V input.

Fan RPM, Delta Temperature And Output Noise

Our mixed noise testing is described in detail here.

The first chart below illustrates the cooling fan's speed in RPM, and the delta between input and output temperature. The results were obtained at 34 °C (93.2 °F) to 47 °C (116.6 °F) ambient temperature.   

The next chart shows the cooling fan's speed (again, in RPM) and output noise. We measured acoustics from one meter away, inside a small, custom-made anechoic chamber with internals completely covered in sound-proofing material (be quiet! Noise Absorber kit). Background noise inside the chamber was below 18 dB(A) during testing, and the results were obtained with the PSU operating at 34 °C (93.2 °F) to 47 °C (116.6 °F) ambient temperature. 

The following graph illustrates the fan's output noise over the entire operating range of the PSU. The same conditions of the above graph apply to our measurements, though the ambient temperature was between at 28 °C (82.4 °F) to 30 °C (86 °F).  

The PSU started our tests with its fan spinning slowly, and not in passive mode as it should have been. More than likely, this was because we were pushing the minor rails right off the bat. Passive mode was triggered afterwards, but not for long. Up to around 350W load, the fan made a bit of noise. For a short time afterward, its speed increased, only to drop again between 400-450W. Beyond 500W, the noise levels increased quickly, and under 600W or more, the noise was very loud.

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  • 10tacle
    Huh. Johnny Guru gave two variants of this PSU series recommended ratings back in Nov. & Dec (650, 850). I saw a 650W on sale at NewEgg last December for $50(US) after rebate and almost recommended it to a friend, but I didn't as I hadn't seen a JohnnyGuru review on the GQ series yet (they gave it a 9.4). They also gave the 850W version a 9.2 rating back in November.

    Not sure what happened with this 750W example, but it sounds more like what one would expect with a Corsair CX750 example. Definitely not the same results that Johnny Guru got with two different GQ variants.
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  • Aris_Mp
    The lower capacity GQ models use a different platform from the higher capacity ones (850W and more).

    The design of the 650 and 750 GQ models doesn't allow for better performance, especially in ripple performance.
    1
  • dstarr3
    Eh, I'd stick with the G2 series. That's a lot more quality for only a small price premium. And really, the PSU is probably the worst place to cut costs in a system build.
    2
  • basroil
    Oh god, another PoS EVGA unit that shares a similar name to the spectacular G2... I can see a flood of "my graphics card has coil whine", "my computer constantly crashes", and "my headphones have static/popping (only when playing games)" posts in the forum soon...
    1
  • joz
    Quote:
    Eh, I'd stick with the G2 series. That's a lot more quality for only a small price premium. And really, the PSU is probably the worst place to cut costs in a system build.

    Agreed. G2 550 and 650's are great. And the P2 750+ if you need that sort of power are great too. But these...."craptacularripplefail," units EVGA is tossing out is really hurting their image. I understand market catering and such, but they need to rethink their strategy. They aren't going to win any price/perf races while Corsair can continue to throw their shitty cx units out the window to customers. And EVGA I hold to higher standards then Corsair, so its kind of a shame to see the performance of these lower quality power supplies.
    1
  • SR-71 Blackbird
    I would take the EVGA G2 , P2 , T2 over any other POWER SUPPLIES including Seasonic.
    0
  • jonnyguru
    Quote:

    Agreed. G2 550 and 650's are great. And the P2 750+ if you need that sort of power are great too. But these...."craptacularripplefail," units EVGA is tossing out is really hurting their image. I understand market catering and such, but they need to rethink their strategy. They aren't going to win any price/perf races while Corsair can continue to throw their shitty cx units out the window to customers. And EVGA I hold to higher standards then Corsair, so its kind of a shame to see the performance of these lower quality power supplies.


    Unfortunately, you can't be too profitable selling only niche higher end product. At some point, if you want the board of directors to let you continue putting out power supplies, you have to put something out that can do volume. The B2 Series, The GQ Series, etc. Don't like them? Don't buy them. Is it hurting their reputation? No. Not as long as higher end units like the G2, P2, etc. continue to be solid. But if they start to slip for whatever reason, then you can say their reputation is in jeoprady. Seriously. Hardly anybody judges the Corvette because of the Chevy Spark (well... maybe some Ford fanboys, but still).
    2
  • SR-71 Blackbird
    I like the GQ's and recommend them , also love the Corsair RMx series and recommend those too.
    -1
  • PureBlackFire
    Quote:
    Huh. Johnny Guru gave two variants of this PSU series recommended ratings back in Nov. & Dec (650, 850). I saw a 650W on sale at NewEgg last December for $50(US) after rebate and almost recommended it to a friend, but I didn't as I hadn't seen a JohnnyGuru review on the GQ series yet (they gave it a 9.4). They also gave the 850W version a 9.2 rating back in November.

    Not sure what happened with this 750W example, but it sounds more like what one would expect with a Corsair CX750 example. Definitely not the same results that Johnny Guru got with two different GQ variants.


    well, this is hardly the first time an FSP platform performed reasonably well at 650 watts and sucked at 750. sure it won't be the last either. as for the 850, like Aris said, based on a different (better) design.
    1
  • 10tacle
    Anonymous said:
    well, this is hardly the first time an FSP platform performed reasonably well at 650 watts and sucked at 750. sure it won't be the last either. as for the 850, like Aris said, based on a different (better) design.


    That's just not right. A certain series should be of the same quality across the series offerings. There's a reason people shop for different series for their needs (budget vs. quality, etc.). Hell it's complicated enough already just trying to keep up with each OEM series line offerings and their quality tiers. I mean we all know the general quality difference between Corsair's CX line and EVGA's G2 line.
    0
  • PureBlackFire
    Anonymous said:


    That's just not right. A certain series should be of the same quality across the series offerings. There's a reason people shop for different series for their needs (budget vs. quality, etc.). Hell it's complicated enough already just trying to keep up with each OEM series line offerings and their quality tiers. I mean we all know the general quality difference between Corsair's CX line and EVGA's G2 line.



    unfortunately engineering is more involved than that. even within those two series you named, there are nuanced differences in the series, even on the same platform. the Be Quiet Dark Pro 11 1200 doesn't perform so great among other high end 1200 watt units, but the 850 watt sits right among the top units at that capacity.
    2
  • 10tacle
    Anonymous said:
    unfortunately engineering is more involved than that. even within those two series you named, there are nuanced differences in the series, even on the same platform. the Be Quiet Dark Pro 11 1200 doesn't perform so great among other high end 1200 watt units, but the 850 watt sits right among the top units at that capacity.


    Yep, I can understand that between the component need differences of a 650W and 1050W in the same series line like Japanese vs. Chinese made capacitors for example. Just goes to show not only do we need to know the general product line, but we really need to drill down to the specific PSU in that product line for true quality measurement. A series lineage alone doesn't guarantee anything.

    I don't upgrade PSUs nearly as often as I do CPUs and GPUs combined, so reviews like this are nice to know in between years of not being in the PSU market.
    0
  • jonnyguru
    Quote:


    Yep, I can understand that between the component need differences of a 650W and 1050W in the same series line like Japanese vs. Chinese made capacitors for example.


    Well... Then you don't really understand because Japanese brand vs. Chinese brand capacitors aren't making the differences you're eluding too. It costs a lot of money to have multiple platforms within the same product line. It typically costs less in engineering costs and BOM cost to reuse the same platform for multiple wattages. Unfortunately, that almost always means that that platform works at its best at one wattage, but not necessarily one higher or one lower.
    0
  • turkey3_scratch
    Out of spec ripple is enough for me to say "no" to a unit. This just proves what I always say: you can't judge a particular power supply based on other models in the series. We did not see this stuff with the 650W and 850W models, too bad the 750W is an under-performer.
    2