Can anyone explain this? - CPU temps rise after reboot.

Hi all,

I noticed this on a few occasions recently. When I turn on the system first thing in the morning the CPU temp is normally lower, on both idle and load. This morning I ran Prime95 for 2 hours and the maximum load temp was 39c.

I then rebooted (happens also if I shutdown for about 40 mins) and ran Prime95 again straight away and this time the maximum load temp was 44c, much higher than just a few minutes ago. 44/45c are what the temps under load normally are throughout the day.

I'm a bit puzzled. Could this happen with Arctic Silver 5. I recently (6 days ago) replaced my heatsink with a SLK-900a and AS5. Previously I used AS3 with an AX-7 heatsink. I never noticed this with AS3, temps were the same even on the first boot.

Tomorrow I might try and leave the computer on when I first turn it on in the morning, without rebooting or shutting down. The were things are, the CPU temp might stay low throughout the day.

If you can understand what I wrote, I would appreciate any comments.

well turning it on in the morning from cold is going to give you diffrent reading than after a reboot, when you reboot the system is under full 100% load for approx 30 seconds depending on the hardware you have, now as the chip was already at X temp instead of ambient its going to go up, the question is, how long does that temp take to stabilize after reboot?

m@

You don't say what mobo you are using but if it is an NF7-S it is a well know foible where the temps after a reboot will be different than on 1st boot. Mine always dropped but some people see it go up ...

Quote:

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Originally Posted by BUFF

You don't say what mobo you are using but if it is an NF7-S it is a well know foible where the temps after a reboot will be different than on 1st boot. Mine always dropped but some people see it go up ...

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Yes, it's an Abit NF7-S v2.0.
Is that normal for this motherboard then?

Yes, the sensor re-calibrates on reboot.
For most people it results in a drop in temp. but for some it goes up.

I am getting completely confused by the CPU temperature sensor on the NF7-S now.

In the mornings (after the system has been off all night) the CPU temp reading is always low and when I reboot they go back to normal.
This evening however I started the computer after it had been off for an hour, and noticed my load temp was high at 48c. So I rebooted, ran Prime95 torture test and then the load temp was 45c, 3c lower.
The nforce2 chipset temps always seem to stay the same.

I may have to install a temp sensor next to the CPU core, I have a couple on a fitted Fan Controller which I do not use. It's becoming hard to tell what my CPU temps are anymore.

I'm using the latest Abit D27 bios, I could try an older bios to see if that helps.