Mark feels the power flow from XFX to dedicated gamers
There was a time when those who bought power supplies just wanted more watts and maybe some dedicated PCIe lines for that demanding video card. But things have drastically changed, and the power demands made by the PC are actually going down.
In that respect, the XFX Pro 850W Black Edition might look rather over-specified in a couple more years, once 14nm and smaller technology filters into the mainstream.
But for those with multiple GPUs or banks of hard drives already installed, something this efficient, well made and engineered should be highly desirable.
XFX previously made a 'Black Edition' 80 Plus Bronze supply that was partially modular, but this design has 80 Plus Gold certification and complete cable modularity.
Therefore even the big ATX24 cables detach, though without it the PC can't demand power from the PSU, so leaving it off entirely isn't a real option.
In most PSU ranges 850 watts is near the top of the range, but here XFX makes a 750W little brother and two 1050VV and 1250W bigger siblings. All of them are rebranded Seasonic X-Series designs, and XFX has followed Corsair in its reuse of this very solid design.
Without any cables initially attached, the Pro 850W makes for a very easy install in most cases, as it's just 160mm long front to back, 150mm deep and 85mm high. The underside is dominated by a 120mm fan, the speed of which is controlled by internal sensors.
One of the immediately attractive features is a small switch that allows 'normal' or 'hybrid' fan mode, the latter of which reduces fan speed and by definition system noise.
In terms of power delivery, 850 watts gives you a predictably large selection, given that once ATX12V/EPS12V are accounted for there are ten connectors to be divided up between SATA (10), PCIe (6 x 6+2 pin), Molex (5) and a single floppy power source.
The breakdown of power is pretty straightforward, with 3.3V and +5V each getting a maximum of 25A, and the + 12V rail getting a massive 70A to play with. Obviously if these all demanded the maximum level it would exceed the power budget, but the 'EasyRail Plus' architecture does avoid having unavailable amps stashed away.
Those wanting to build a multi-GPU rig need to consider just how much each card will draw, because there are cards like the monster GTX Titan Z that pull 42A, and you'd really only want one of those on this PSU.
Conversely, as they only draw 20A, three GTX 960s might well be fine. However, I'd recommend that anyone getting close to exceeding the limit should move up to the next wattage rung and give themselves plenty of extra head room.
As supplies go, the XFX Pro 850w Black Edition is a classy act with a strong pedigree and a five-year warranty. And I'd contest if you treat it right, it should be working long after that. Mark Pickavance
Great-quality PSU with enough amps for most people.