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EVGA GQ Series 750W PSU Review

EVGA teamed up with FSP once again to produce the new GQ line, which is one step below the highly popular G2 series. The four GQ PSUs feature 80 Plus Gold efficiency and semi-modular cabling, promising quiet operation.

Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

In these tests, we monitored the response of the PSU in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V and 0.5A at 5VSB) was applied for 200ms while the PSU worked at 20 percent load. In the second scenario, the PSU was hit by the same transient load under a 50 percent load. In both tests, we used our oscilloscope to measure the voltage drops caused by the transient load. The voltages should have remained within the ATX specification's regulation limits.

These tests are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call these tests "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for a PSU with a capacity of less than 500W.  

Advanced Transient Response at 20 Percent

VoltageBeforeAfterChangePass/Fail
12V12.104V11.894V1.73%Pass
5V4.961V4.829V2.66%Pass
3.3V3.277V3.123V4.70%Fail
5VSB5.077V5.029V0.95%Pass

Advanced Transient Response at 50 Percent

VoltageBeforeAfterChangePass/Fail
12V12.050V11.856V1.61%Pass
5V4.938V4.793V2.94%Pass
3.3V3.252V3.074V5.47%Fail
5VSB5.044V4.993V1.01%Pass
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ACRF topologies usually doesn't do well in transient response tests, and that's exactly what happens here. The +12V rail registers high deviations on both tests, as does the 5V rail. Still, the worst performance comes from the 3.3V rail, which fails to keep its load regulation in spec on both tests. Clearly FSP should improve this platform's transient response performance. And that's no easy request, since it could lead to lower performance in other areas.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load

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Transient Response At 50 Percent Load

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Turn-On Transient Tests

In the next set of tests, we measured the response of the PSU in simpler transient load scenarios—during the PSU's power-on phase.

For the first measurement, we turned off the PSU, dialed in the maximum current the 5VSB could output and switched on the PSU. In the second test, we dialed the maximum load the +12V could handle and started the PSU while it was in standby mode. In the last test, while the PSU was completely switched off (we cut off the power or flipped the PSU's on/off switch), we dialed the maximum load the +12V rail could handle before switching on the PSU from the loader and restoring the power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5V for 5V).    

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We measured a notable spike at 5VSB, which was below the limit, and a smaller one during the last test. Overall, the performance here is average due to the high 5VSB spike at 5.32V.

  • 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.
    Reply
  • 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.
    Reply
  • 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.
    Reply
  • 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...
    Reply
  • joz
    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.
    Reply
  • Dark Lord of Tech
    I would take the EVGA G2 , P2 , T2 over any other POWER SUPPLIES including Seasonic.
    Reply
  • jonnyguru
    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).
    Reply
  • Dark Lord of Tech
    I like the GQ's and recommend them , also love the Corsair RMx series and recommend those too.
    Reply
  • PureBlackFire
    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.
    Reply
  • 10tacle
    17373323 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.

    Reply