I just built s new system with an intel core i7 920 on an evga x58 motherboard. A few minutes after loading the BIOS(Phoenix BIOS), the CPU supposedly reached 85 degrees Celsius. In Windows Vista, the four cores give readings from 98-100 degrees Celsius. I'm hoping there might just be something wrong with the temperature sensors, wouldn't there be stability issues with a cpu that hot? I'm keeping the computer off right now, and thinking of reseating the heatsink- but even if the heatsink were a little bit off, would the cpu reach that temperature- let alone run stably?
Use Realtemp or Coretemp, and trust the temperature reported in BIOS - at least for now lol.
Yes, check and re-seat the heatsink. It would be best to remove the mobo if you need to in order to see that each of the four "legs" has passed through the mobo and each leg's split-pins are locked securely underneath it by the pin you pushed through the center. (Assuming you used the stock cooler, as you didn't specify.)
As for temps, stability . . . its all a matter of degrees
I have an i7 920 and I also found it ran very hot. Right now, I have a TRUE with two fans on it and it still runs in the high 70s to low 80s when under 100% load at 3.6ghz. This is the hottest of the four computers I have. So if you still have the stock heatsink, I'd dump it and get an aftermarket one, the biggest and best that you can afford. Besides the TRUE, the Coolermaster V8 and V10 are good, as well as the Noctua, which has the advantage of being nearly silent.
I am seeing idle temps between 50-54C with my i7-920. And under load it only tops out at around 65. I just put some Diamond IC 7 on it and I didnt bother to get temps before and after, since it didnt fry yet I am assuming everything is making contact.
My 360M GTS idles around 75C and hits 80C under load.