Performance, Performance Per Dollar, Noise, And Efficiency Ratings
The following graph illustrates the 850 BQ's total performance rating, comparing it to other units we have reviewed. To be more specific, the tested unit is shown as 100 percent, and every other unit's performance is shown relative to it.
EVGA's overall relative score is pretty low, mostly because of loose load regulation and increased ripple on the minor rails, along with the 3.3V rail's poor response to transient loads.
Performance Per Dollar
The following chart may be the most interesting to many of you because it depicts the unit's performance-per-dollar score. We looked up the current price of each PSU on popular online shops and used those prices and all relative performance numbers to calculate the index. If the specific power supply wasn't available in the United States, we searched for it in popular European Union shops, converting the listed price to USD (without VAT). Note that all of the numbers in the following graph are normalized by the rated power of each PSU.
EVGA's asking price is pretty affordable, so the 850 BQ's performance per dollar score is only a little lower than the CX750M's.
The graph below depicts the cooling fan's average noise over the PSU's operating range, with an ambient temperature between 28°C and 30°C (82°F to 86°F).
The 850 BQ is noisy, no doubt about it. This is a great shame because, with a lower minimum fan speed, it could be much quieter.
The following graph shows the PSU's average efficiency throughout its operating range, with an ambient temperature between 28°C and 30°C.
Efficiency lands in the 80 PLUS Bronze region, unsurprisingly. If you need higher efficiency, then you have no other option but to invest in a Gold-rated unit. Of course, that's going to cost more, too.
Why is that?
As for more 450-550W PSU reviews, I am currently working on a 500W unit (which however isn't affordable).