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EVGA SuperNOVA 550 G2 PSU Review

EVGA introduced two new low-capacity G2 PSUs. Today, we evaluate the 550 G2 model made by Super Flower, which features 80 Plus Gold efficiency.

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 to the PSU for 200 ms while the PSU was working at 20 percent load. In the second scenario, the PSU was hit by the same transient load while operating at 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, an instant 100 percent load of CPU/GPUs, etc.). 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
12V12.249V12.162V0.71%Pass
5V5.056V4.957V1.96%Pass
3.3V3.304V3.207V2.94%Pass
5VSB5.056V5.017V0.77%Pass

Advanced Transient Response at 50 Percent

VoltageBeforeAfterChangePass/Fail
12V12.215V12.126V0.73%Pass
5V5.044V4.948V1.90%Pass
3.3V3.293V3.190V3.13%Pass
5VSB5.019V4.985V0.68%Pass
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Although the relatively low capacity doesn't help in these tests, the 550 G2 unit managed to register a very good overall performance, especially at +12V, which is the most important rail. We were very pleased to see +12V staying well within 1 percent, with only the 3.3V rail going above 3 percent during the second test.

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 switched off the PSU by flipping its 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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There were no spikes of voltage overshoots here. The Leadex platform handles turn-on transients really well. 

  • marraco
    Wow. Ripple behavior is fantastic.

    I would like to see another test. I had a PC with a Coolermaster PSU and 4 HD which were put to sleep mode/hibernation. Sometimes when the 4 HD were powered up the PC hanged, because the 4 HD demanded so much transient power that it threw the PSU voltages out of specs.

    I was thinking that I had a great PSU, but it was expensive garbage.
    Reply
  • Aris_Mp
    this scenario is covered by the transient response tests, which I conduct in page #7 of the review.
    Reply
  • giantbucket
    i don't get it... isn't this like trying to sell a Ferrari with only 3 cylinders to appeal to the sub-$100,000 clientele?
    Reply
  • dstarr3
    Super Flower makes some great hardware. I'm all over this for my upcoming modest gaming rig.
    Reply
  • damric
    It's all about the LEADEX.
    Reply
  • dstarr3
    i don't get it... isn't this like trying to sell a Ferrari with only 3 cylinders to appeal to the sub-$100,000 clientele?

    The problem is that all of the best-built, best-featured PSUs were being made in 850, 1000, 1200, 1600W variants. If you had just a modest system, something mid-range, you either had to get a PSU that was way overkill, or you had to settle for PSUs that weren't so well built, or as efficient, or as fully-featured. So, this is an attempt to distribute very high-quality products to more of the market. And I am 110% A-Okay with that.
    Reply
  • MasterDell
    i don't get it... isn't this like trying to sell a Ferrari with only 3 cylinders to appeal to the sub-$100,000 clientele?

    The problem is that all of the best-built, best-featured PSUs were being made in 850, 1000, 1200, 1600W variants. If you had just a modest system, something mid-range, you either had to get a PSU that was way overkill, or you had to settle for PSUs that weren't so well built, or as efficient, or as fully-featured. So, this is an attempt to distribute very high-quality products to more of the market. And I am 110% A-Okay with that.
    I agree with this to some extent because there are and were tons of PSU's made by Seasonic. Whether they were Antec units or XFX units OEM'd by Seasonic or not.. They were made by Seasonic. Now, as for fully modular, gold rated variants, those were and still are far and few between. However there are tons of Bronze semi-modular/none modular units which are great for mid-range builds.

    I actually own this unit and used it in a build with a 960. I got it right when it came out and for it's price, it offered a ton. I live in Canada and PSU's are way over-priced and the prices make no sense on them. But this unit was priced extremely well likely due to it's availability so I picked one up. No problems and I am glad EVGA is filling this market void. Good on em.
    Reply
  • Nuckles_56
    Nice to see a low wattage power supply being reviewed for a change and particularly one which performs very well
    Reply
  • turkey3_scratch
    I think I found my PSU. I don't need any 750W, but I had trouble finding a high quality 550W unit, and this is it!
    Reply
  • g-unit1111
    I have two G2s, these are far and away some of the best PSUs on the market! Good to see that EVGA is making some lower wattage models that have the same quality and consistency.
    Reply