My mate is having problems with his pc, see spec below. Random (?) crashs. Has tested with just one graphics card and it was stable. AMD 4000 64, X-Fi fatality, BFG PhysX card, ATI X1900 Crossfire, ATI X1900XT, Raptor 74GB, WD 200GB, OCZ Powerstream 600w, Asus A8R32-MVP Deluxe Crossfire (Socket 939) PCI-Express Motherboard. The psu doesn’t have a fan underneath drawing air up and out, it’s a passthrough from front to back, 2x Arctic Cooling Accelero GPU coolers, Akasa Evo33 CPU cooler, 2x 120mm case fans. There is unobstructed airflow from intake to add in cards. Heat is definitely an issue, but on some of the crashes, after a restart there is no vpu recover message, so this makes me think it is a psu problem, especially as I cannot restart until after I have switched off and on the psu at the back of the case. I have had a large room fan blowing directly into the case as well, still it crashes. I can leave the desktop on for days on end, it runs fine until I start to do something intensive. Is the psu big enough, max output on the 12v rail is 13.2v, case is Akasa Eclipse does he need bigger for better airflow ?