EVGA BQ Series 850W PSU Review

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

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

Transient Response At 50 Percent Load

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).

There are no voltage overshoots or spikes to mention. Instead, we observe good performance, especially for a budget-oriented PSU.

25 comments
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  • joz
    At $85 I can get a G2 650W; or even a G2750W on sale.
  • Metteec
    Thanks for the review. Looks like I will be avoiding this one.
  • 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.
  • _TheD0ct0r_
    1547864 said:
    Thanks for the review. Looks like I will be avoiding this one.


    Why is that?
  • 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.
  • MasterMace
    appears to be another terrible unit. I'll have to read back and see if it's an Andyson or a HEC
  • Dark Lord of Tech
    Considering the OEM is HEC , not surprised by this review.
  • 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
  • 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.
  • 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).
  • logainofhades
    Given the fact that a B2 850 is selling for a couple dollars less, there is no reason to even think about this BQ.
  • lunyone
    1903369 said:
    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).


    So is all of your reviews come from a retail purchase, or are there some delivered from whichever vendor? Just curious, because I remember reading not too long ago that pretty much all of the products had been items that were submitted from whichever vendor. So I'm guessing that 90-95% of reviews come from vendor delivered samples or am I wrong in that assumption? I'm just curious and not trying to be a troll or anything like that. I think it would be beneficial if the viewer knew whether or not the sample was purchased or offered/delivered from said vendor.
  • Dark Lord of Tech
    The samples come direct from the Manufacturer.
  • lunyone
    276663 said:
    The samples come direct from the Manufacturer.


    Yes I understand that. Aris_MP stated that it came from the Store shelf, so I was trying to get an idea on how many items have been purchased from a Store shelf compared to the ones that the Manufacturer delivers to the reviewer.
  • Dark Lord of Tech
    Most of the time , with most reviews they aren't off the shelf , this is rare , they are sampled direct.
  • Aris_Mp
    Like in almost all product reviews, PSU samples come directly from the manufacturer, which also provides support in case the product breaks down (something that is very easy to happen in a PSU review). Besides a huge budget buying the products from a store would also mean no support in case the PSU dies, since its warranty is voided the moment I set it on my test bench.
  • lunyone
    1903369 said:
    Like in almost all product reviews, PSU samples come directly from the manufacturer, which also provides support in case the product breaks down (something that is very easy to happen in a PSU review). Besides a huge budget buying the products from a store would also mean no support in case the PSU dies, since its warranty is voided the moment I set it on my test bench.


    So the units that you get from the Manufacturer could be cherry picked, even though they still cover any/all issues during the review, which is the point that I was trying to make about getting units that aren't always indicative of what a consumer would experience from buying the product. Not saying this is bad, just pointing it out.
  • Aris_Mp
    yes they could. But this doesn't mean that every manufacturer does that. Even if you buy samples there is always the possibility for changes in the manufacturing line and the next batch to be worse (or better). So you never know.

    Personally I rely on my experience, knowledge and connections to find out not-proper (AKA Golden) samples. There are times that even my readers provide useful tips. E.g. when they do notice a different part in their PSU and report it. This is why I fully break apart every PSU (and all the rest samples in the sites I work for) during a review, a procedure that takes many hours and can be quite hard some times (for instance when you have to fight with Enhance Electronics' huge heatsinks).
  • lunyone
    Oh I understand your troubles that you have to go through. I think it would be more fair, if the manufacturer would allow you to purchase their product from a retail store of your choice and offer the same support throughout your review period. Of coarse re-reimburse you for the cost of the purchase price. This would show the viewer/reader what kind of experience/product that one would expect if they went out and bought said product. I know it isn't going to happen that way, but I feel that would be the best of both worlds. You (the reviewer) would get the support you need from the manufacturer and the viewer/reader would know that the reviewer had purchased the product locally (if possible) and this would reflect a more realistic review of a retail sample.
  • madmatt30
    I don't get it at all.
    While not an inherently bad unit it just seems completely pointless really.
    The fsp made gq850 is just better & its the same price.
    I can understand evga using hec for the budget orientated b1 series but not 850w modular units that are aimed at higher end users.
  • logainofhades
    1031363 said:
    I don't get it at all. While not an inherently bad unit it just seems completely pointless really. The fsp made gq850 is just better & its the same price. I can understand evga using hec for the budget orientated b1 series but not 850w modular units that are aimed at higher end users.


    Yea, when they already had the superflower built B2.
  • Marcus52
    I don't know why EVGA would even consider offering this kind of product. They're supposed to stand for quality, not cheap.
  • Nuckles_56
    59887 said:
    1031363 said:
    I don't get it at all. While not an inherently bad unit it just seems completely pointless really. The fsp made gq850 is just better & its the same price. I can understand evga using hec for the budget orientated b1 series but not 850w modular units that are aimed at higher end users.
    Yea, when they already had the superflower built B2.

    Probably because they are about to discontinue to SF built B2 in favor of this unit
  • logainofhades
    Which would be a horrible idea, as the SF built unit is a far better.