Installing The Power Supply
Upright, And A Choice Of Left Or Right
There are two viable mounting locations for the power supply, so you can take your pick (unless of course you'd like to install two power supplies, which is also possible). In both cases, the PSU sits upright. This isn't particularly ideal for passively-cooled power supplies, but it shouldn't be a problem for units with fans.
The shot below shows that there's plenty of room, even for extra-deep power supplies. If your power source of choice is less than about 7.5" deep, you can mount a drive cage in front of it. Don't feel pressured to, though; this case already offers tons of interior space for storage.
The power supply sits on the bottom of the case, without any sound-proofing material. I don't think a thin rubber pad for isolation is too much to ask for in this price category.
I hooked up my microphone and concluded that relatively quiet power supplies probably won't present any vibration problems. But if you plan to mount an older PSU with a large or unbalanced fan, the lack of acoustic decoupling could result in additional noise.
Putting this minor concern aside, I wanted to address a more pressing question: does the upright position result in higher power supply temperatures? I measured Corsair's AX1200i sitting up and loosely positioned on its back, recording zero different between the two orientations.