Maximum PC

I have a Corsair 650w PSU powering an
MSI 770-G45
Phenom II X4 955
Radeon 5870
and 1 sata drive

During normal use the PSU feels very warm, and during gaming it's hot to the touch. It also heats up the top of my case quite a bit.

It seems like the PSU fan isn't running that fast though. There's barely any air coming out of it
The PSU intake fan is right above the CPU cooler, maybe that's why?

All my other (low end) computers, the (cheapie no-brand) power supply is cold even being on for 24+ hours.

Heat kills components, correct?
So i'm about to mod my case so the psu intakes from outside the computer

Case blowholes work wonders, but still don't think the PSU you have should be hot to the touch with that type of hardware payload. I've felt my 750's get pretty warm, but had some power suckers attached and loaded pretty heavily.

Right now, you should show about 400-450W loaded (CPU and GPU) at the socket I'm guessing, and is well within a 650TX's capability really. Come to think of it, you may be right about the bottom fan sucking in some warm air. If you're going to flip the fan around, just be careful in there.

What's the ambient temperature?

Maybe try a bit of flexible duct to try and draw from outside?

I flipped the entire power supply upside down and cut a hole on the top of my case.







Yeah, that is a piece of cardboard. To insulate the powersupply from the CPU. I wonder if it actually helps though.

Edit:
Furmark + Prime95 for an hour, air coming out of psu is 45C
which looks normal. But the PSU is still hot to the touch. idunno

I've got a Corsair 950TX. Idling my rig pulls 240w and playing Crysis, it's hitting 700W. The PSU can get pretty warm to the touch, but Corsair fans are temperature controlled in these two PSU's IIRC. It's not anything I would worry about as long as the fan does come on. PSU's can take the heat, you just don't want it heating up the rest of your case.