System: Striker II extreme 790i ultra - q9550 @ 2.83 (stock) - stock heatsink - 4GB ddr3 1333 - 9800gx2 - cosmos s case (stock cooling)
Context: got system 6 months ago, had what i thought to be cpu temperature problems (60-65C load, rare 40C idle(mid 40s usually)). Read up in forums across the net and concluded i couldnt expect anything less with stock cooler and quad core.
For the longest time, I kind of gave up on the whole heat issue and decided it was in fact normal.
I just update my bios to the most recent version (from stock 0402 to 1104) and something extremely mysterious went down:
after the bios flash, I immediately opened everest to make sure all systems were stable (temps, fans ect.), and my jaw just dropped:
Temperatures (right after windows vista 64 load) were jumping between 38C and 45C!!!! Normaly they would be between 59C and 64C
I trippled checked with pc probe and ai suite and everything checked out.
I am now running full throttle at 45C MAX with no performance change, even maybe increase.
What happenned? is this normal?
Is my new bios right? is it just a buggy reading? was my old bios wrong? did the temperature actualy change?
Thank you all for your feedback
ne and all greatly appreciated
lw, as your earlier BIOS dates to around the time of the q9550's introduction, I bet it didn't have the updated calibration information for the q9550's internal thermal sensors.
Assuming you are referring to a single overall CPU temp rather than temps for the individual cores, the reported temp value relies on a CPU-specific data table in the BIOS to convert measured readings into temperatures, and thus depends on your BIOS having the correct calibration info for your specific CPU.
The digital temp sensors in each CPU core on Intel chips provide direct digital readings, so you should go and compare your overall BIOS-reported CPU temp with the individual core temps that programs such as "coretemp" provide.
The on-die analog thermal diode from which CPU temperature is sampled is converted to a digital value by the super I/O chip on the motherboard, and is then calibrated in BIOS to processor specific tables, as Mondoman has explained. As BIOS programmers must code all socket 775 variants into each update, it's not uncommon for mistakes to show up, whether subtle or glaringly obvious.