Power Supplies

The load level you should shoot for is 50% of the total 12V output. What constitutes load is a bit trickier - especially for gaming systems. You need to research high-to-maximum power consumption at your desired clock speed (OCing consumes some extra power, overvolting as well consumes a lot more power!) for your current/desired CPU and all GPUs. Don't use results derived from Crysis or torture tests like OCCT/Perestroika, FurMark or IBT/Linpack to provide the "average load" figure for this as they can actually drive hardware past normal thermal specs and we're not looking for worst-case figures here. The latest 3DMark with some lower-priority protein folding in the background to eat spare CPU cycles gives "normal" gaming consumption with a slightly-pessimistic CPU power spec and is what a gaming system needs to match to the 50% mark. Then so long as the above torture tests pass below the 90% mark (hugely unlikely) you're golden. Crysis may gobble juice but it isn't the only game you play so don't sweat it if reviews suggest it would push you to the 60-70% mark. Folders need to pay attention to the CPU power usage a bit more than other gamers as few games push the CPU to 100% consistently let alone breaking point; OCCT on the other hand just isn't normal usage.

Unless you have a Gigabyte Odin GT you have to get all those figures off the web to boot Xbit Labs is the best; I've been able to confirm their findings with my Odin's integrated DVMs. There are other resources out there but they tend to be less accurate or contradict themselves at times.

Multi-rail PSUs are not the work of the Devil. Don't let flim-flammery confuse you about that. The only time there's an issue is if you tried to run a HDD-heavy server on an older multi-rail PSU that tries to lump all system power from fans and drives, the mobo, the first 75W of each GPU and most and sometimes even all the CPU consumption on just one ~200W rail. Then when the HDDs all spun up together at startup you could trip the OCP and crash out before the OS finished booting

Superflower (and the NZXT and KingWin rebadges) are on top form. Their Gold and Platinum units are still very pricey AFAIK, but they're the best on the market.

At the moment the most contentious niche is the low end gaming-grade, as it is hugely 12V-based and some awful PSUs from otherwise-reputable names have been doing the rounds, based on late Pentium 3 (i.e. 5V-based) designs with a reinforced 12V rail. The small 3.3V/5V load on such systems is insufficient to keep the 12V rail at 12V, or even 11V while gaming! :eek:

The revamped Cougar A-series are good budget units AFAIK, the 350W and 400W units actually look to be underrated!

The Corsair CX500/600 are also decent enough for the price AFAIK, its only the CX430 which sucks in a truly astonishingly vile way

IIRC most of the more powerful Coolermaster units are decent, but don't touch GX/HX units or older ones under 700W with a bargepole.

be quiet! and Antec's Basiq units are average, but will do in a pinch.

Avoid the really cheap basic Superflower units - only get the Amazon units or better. Avoid Jersey/RaidMax/ChiefTec/DiabloTek/Xilence and most Xigmatek PSUs like the plague! Avoid anything under €30 like it has freakin' Ebola! :eek: