Test ResultsLike in the 400W-500W roundup, we calculate output power and efficiency based on the pass or fail settings the PSU made it to during torture testing. The results are as follows.
Please note that the original published version of this article calculated effiency using ideal output power, not actual. The table has been updated to reflect that fact and any article text updated accordingly. Please be aware that the change in efficiency figures in no way affect our conclusions as originally published
|Readings under load||Power & efficiency|
|PSU||+12V1||+12V2||+12V3||+12V4||+5V||+3.3V||-12V||+5VSB||Input power||Ideal output||Actual output||Original Incorrect Efficiency||Corrected Efficiency|
|Coolermaster iGreen Power 600W||Voltage||12.005||12.0125||12.1625||4.6675||2.8675||-12.275||4.8475||747.4W||613.4W||601.10W||82.1%||80.43%|
|FSP Epsilon 600W||Voltage||11.82||11.827||11.877||11.917||4.82||3.05||-12.467||4.9775||731.8W||610.7W||600.78W||83.5%||82.1%|
|Seasonic S12 Energy+ 650W||Voltage||11.765||11.85||11.8925||11.9225||4.83||3.1375||-12.4125||4.88||784W||662W||651.99||84.4%||83.2%|
|FSP Epsilon 700W||Voltage||11.7725||11.82||11.81||11.875||4.795||3.0025||-12.49||4.9525||886W||721.6W||706.66||81.4%||79.8%|
|OCZ GameXStream 700W||Voltage||11.73||11.77||11.7775||11.825||4.77||3.025||-12.345||4.9625||807W (870W)||718.3W||701.36||89.0%||86.9% (80.62%)|
|Tagan Dual Engine 700W||Voltage||11.51||11.65||11.59||11.625||4.825||3.065||-12.465||4.8825||873.7W||726.6W||700.73||83.2%||80.2%|
Every PSU passed testing at its rated output power without fuss or bother, showing that every tested unit is one you could have confidence in, performance wise.
Indeed, all bar the Tagan posted efficiencies of over 80% at max load, with rail numbers as solid as you like. Just the OCZ did that touch better than the rest. Be aware that not all load conditions are equal, mostly down to how the PSUs are configured internally, but that it doesn't skew the ratings enough for us to care, especially in this case when they're all so good. We test like we do to root out the stinkers, and all did nicely, making the number on the box with nary a care.
|PSU||Ambient (°C)||PSU idle (°C)||PSU after load testing (°C)||Calculated Delta (°C) (load - idle)|
|Coolermaster iGreen Power 600W||22||22||31||9|
|FSP Epsilon 600W||22||22||28||6|
|Seasonic S12 Energy+ 650W||22||22||28.5||6.5|
|FSP Epsilon 700W||30||30||38||8|
|OCZ GameXStream 700W||30.5||31.5||38||6.5|
|Tagan Dual Engine 700W||22||22||31||9|
Those in orange were tested on a different day, before the others, with much higher ambient temperature in the testing room. Bear that in mind when taking in the results.
Each PSU deviates by between 6 and 9.5°C over ambient, indicating they all cool themselves fine under maximum load. Note that temperature testing is done out on the bench, free of a chassis, which is where we'd expect the Tagan to do a bit better, comparatively speaking, than the rest. It's fan arrangement is best for a high-output supply, we reckon, compared to the other 120mm fan models.
None of the tested supplies gets overly warm under load (compared to their idle temperature), though, with the Seasonic, OCZ GameXStream and FSP 600W doing best of all.