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EVGA BQ Series 850W PSU Review

One of EVGA's most affordable power supply families, the BQ, includes five unique models. The higher-capacity ones are made by HEC and the rest come from Andyson. Today we're testing the flagship 850 BQ.

Transient Response Tests

Advanced Transient Response Tests

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

Ιn these tests, we monitor the 850 BQ's response in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V, and 0.5A at 5VSB) is applied for 200ms while the PSU works at 20 percent load. In the second scenario, EVGA's contender is hit by the same transient load while operating at 50 percent load. In both tests, we use our oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain 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
12V12.195V12.107V0.72%Pass
5V5.071V4.922V2.94%Pass
3.3V3.384V3.198V5.50%Pass
5VSB4.998V4.945V1.06%Pass

Advanced Transient Response at 50 Percent

VoltageBeforeAfterChangePass/Fail
12V12.123V12.026V0.80%Pass
5V5.021V4.872V2.97%Pass
3.3V3.336V3.154V5.46%Pass
5VSB4.948V4.890V1.17%Pass
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The +12V rail's performance is quite good in these tests, and the 5V rail manages to stay within 3%. Deviations on the 5VSB rail are low as well. By far, the worst-performing rail is the 3.3V one; it registers close to 5.5% deviations on both tests. Thanks to a high initial voltage, though, the 3.3V rail manages to stay above the corresponding ATX limit (3.14V) the moment our transient load is applied.

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 PSU's response in simpler transient load scenarios—during its power-on phase.

For the first measurement, we turned off the 850 BQ, dialed in the maximum current its 5VSB rail could output, and switched the PSU back on. In the second test, we dialed the maximum load the +12V rail could handle and started the 850W supply while it was in standby mode. In the last test, while the PSU was completely switched off, we dialed the maximum load the +12V rail could handle before switching it back on from the loader and restoring 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 are no voltage overshoots or spikes to mention. Instead, we observe good performance, especially for a budget-oriented PSU.

  • joz
    At $85 I can get a G2 650W; or even a G2750W on sale.
    Reply
  • Metteec
    Thanks for the review. Looks like I will be avoiding this one.
    Reply
  • Metteec
    Also, for $20 more, you can pick up an equivalent gold rated PSU or maybe even a platinum one on sale and after rebates. It is the halcyon days for competition in quality PSUs.
    Reply
  • _TheD0ct0r_
    19020704 said:
    Thanks for the review. Looks like I will be avoiding this one.

    Why is that?
    Reply
  • Metteec
    @_THEDICTOR_, for $85, there are so many other better options. EVGA could have been more competitive model if they made quieter version. Instead, you get a PSU with fixed cables, low efficiency, high power variances, and noise like a mini-vacuum. While the higher quality capacitors and warranty are nice, the lack of utility does not make this a good value. 3-years ago, this would have been a great PSU, but times have changed. It is a great day to buy a PSU, just not this one.
    Reply
  • MasterMace
    appears to be another terrible unit. I'll have to read back and see if it's an Andyson or a HEC
    Reply
  • Dark Lord of Tech
    Considering the OEM is HEC , not surprised by this review.
    Reply
  • Nuckles_56
    I would have thought that EVGA could have pushed HEC a bit harder and got a much better unit out of them than this
    Reply
  • lunyone
    I would personally like to see more 450-550w PSU reviews, not the cherry picked and delivered 750w+ ones that seem to make the rounds. It is just that most people are only going to need 450-550w PSU's for their 1 dGPU based systems.
    Reply
  • Aris_Mp
    This is not a cherry-picked sample. It comes directly from a store shelf and not from EVGA.

    As for more 450-550W PSU reviews, I am currently working on a 500W unit (which however isn't affordable).
    Reply