BIOS Temperature Accuracy

[Tanaros]

I have built/am building a new system with an E8400; it's mostly complete except that I don't have any drives for it, so I can't finalize the install. So, keeping in mind that this is a fresh build, and I can't do much more than fire it up and peer in the BIOS, I've got a temperature question.

I'm using a Noctua NH-U12P with two Noctua NF-P12 fans in push-pull configuration, currently sitting in the case with no side panels on. The ambient temperature in this room is ~21 C (~70 F), and the idle temperature on the CPU is 32-33 C sitting in the BIOS at stock speeds. It was initially 36 C, but it reduced a bit after I cleaned the heatsink, reapplied the thermal paste (using Arctic Silver Ceramique as it's what I had lying around), and reseated it.

Are these temperatures something to be concerned about? I haven't done much overclocking in the past, so I don't know how reliable the BIOS temperature sensors are. It seems rather high for idling at stock speeds, given that Anand's review showed 33 C for an idle X6800 @ 3.83GHz with the same cooler.

 

[Rubycon]

BIOS temp does NOT equal idle temp!

 

[Tanaros]

Ah, fair enough. Is there a link somewhere to the "official" (well, you know what I mean...) definition of idle and load temps?

Most of the temperature monitoring is focused on a few applications (CoreTemp, HWMonitor, etc), so where do BIOS temperatures fit into the overall picture? Not generally used?

 

[Rubycon]

Idle temps = Windows NT system at desktop using HLT instructions. In the BIOS your temperatures will eventually climb to where they would be in Windows running a stress test program! So it's not uncommon to see 45-50C in the BIOS if you let it sit there for a while. It won't get as hot as running a max stress like linpack or prime95 small fft but it will be considerably higher than running at the windows desktop with 0 cpu load.

 

[j0j081]

Originally posted by: Rubycon
Idle temps = Windows NT system at desktop using HLT instructions. In the BIOS your temperatures will eventually climb to where they would be in Windows running a stress test program! So it's not uncommon to see 45-50C in the BIOS if you let it sit there for a while. It won't get as hot as running a max stress like linpack or prime95 small fft but it will be considerably higher than running at the windows desktop with 0 cpu load.

why is that? I have never understood it.

 

[Ratman6161]

Originally posted by: j0j081

why is that? I have never understood it.

Because the OS is sending halt commands to the cpu. Basicially it has to be commanded to Idle-it wont do it by itself. With no OS running, there isn't anything to issue those instructions.