I have a AMD Phenom X4 940 (Quad Core) Overclocked to 3.7GHZ and it idles at 50... I think I have a thermalright ultra 120 cooler for the cpu.. I forgot... been years since I bought it.
I have a 460 MSI GTX cyclone (big cooler) Overclocked
it idles at 47
My setup doesn't crash except when I use PCSXE which is a ps2 emulator... and it's likely its fault
High idling temps aren't really a bad thing, besides heating up your house by being inefficiant... and indicate that your load temps could be insanely high and then cause crashes.
For example... I'm not sure about your card... but Nvidia 8800gt's used to idle in the 80-90 C. I don't know about ATI.
Crappy thermalgrease can harden... which is why some ps3' ylod over time, cause sony was cheap... Don't use crappy thermalgrease. If you buy good thermal grease like arctic silver or a gazillion others... you should never have to replace it unless you take the heatsink off.. THEN you should replace it.
Other problems can be virus, or a card that's crapping out. Lots of things.
