i have a variety of dual core and quad core machines-when I run the Prime95 torture test, some of them fail with a rounding error on 1 of the cores-some immediately, and others after a few hours. well the reason I am stress testing these computers is because they seem faulty in some way(random crashes and lockups) but have passed a memtest and even had their peripheral compenents taken out of the mix or replaced(like ram, video cards, powersupplies, hard drive, ect...). so the only thing I have left to test is the processor or some core part of the motherboard bios. I buy and test hundreds of computers-usually bought in bulk and in exactly the same configuration to lessen the likelyhood of a config problem.
does this indicate a faulty processor? bad motherboard? inadequate cooling?
