rapid rise and fall of cpu temps,whats going on?

[desmocat]

Here is something for the inquiring mind.
I am running a 750 T-bird @950, on an Abit KT-7(non raid)with 256 megs pc133, win98se.
I decided to do a reinstall of the OS and did so yesterday. The board as you know has the VIA hardware monitorsystem V2.04 to read cpu temps. Before I did the reinstall,idle temp was around 90-94 degrees F.
After the reinstall, I ran the chip to 1100 MHz to see if it would handle it@1.8V and it would post and go to load windows sometimes OK, sometimes BSOD. CPU temp was at about 122F.
Did it at 1 Gig and was semi stable but occasional crash/lockup, CPU temp='bout114

Backed it down to 950 now, rock stable! and now CPU temp at idle= 80-82 degrees F!!
What seems strange to me is before, I would monitor the cpu temp and it would rise and fall pretty slowly, but now, when I open apps or up/download stuff, the temp goes up like 1-2 degrees every 2 to 4 seconds, then will fall just as fast after activity stops..

HMM, I read somewhere a while back about CPUs reaching a point after they were heavily stressed/burned in that afterwards they would then drop their operating/idle temp below what it was before it was stressed/burned in.
I really didn't put alot of stock in this idea,but it has seemed to have happened to me. Has anyone here had the same happen to them? I don't know if I should believe the temp monitor or not now, since I did do a reinstall of the OS AND try to go ballistic with the O/C. I am wondering if something happened to make the temp monitor start reading wacky...
Any thoughts from anyone about what may be going on?

[Hellmund]

Yeh I've had similar thing happen to me. My Duron 750 was at 66C when I first got it, I left it going for a while on idle at this temp and it slowly fell.Next time I booted it was 55C then 50C......now it idle at 35C and rarely passes 50C even after hours of UT.
I've got roughly the same setup, Abit KT7 without raid, only 128meg PC100 and win98se. I haven't o/ced yet as I'm waiting for a store to stock a FOP-38. I've already got a few loud fans going so noise isn't an issue.

[paul233]

I have not noticed any difference when new or used on any of my amd processors, (333, 450, d600, d800, tb1.2), but the duron and tb definately heat up and cool down quickly depending on cpu use, like a couple degrees every few seconds.

[Bovon]

Read these threads. They generally pertain to the Iwill boards, but I think the utility works wit any of the KT133a chipset boards.

This site also has sections for all of the mainboards that are designed for the AMD processors.


The utility:
http://www.athlonoc.com/tweakvia2.htm

The discussion threads:
http://www.amdmb.com/vb/showthread.php?threadid=29079
http://www.amdmb.com/vb/showthread.php?threadid=32671

[desmocat]

Thanks for the threads Bovon,there's alot of interesting reading there http://www.sysopt.com/forum/smile.gif

[Peter M]

I guess your previous OS install didn't use any power management features. As it is now, it sounds as if your new installation puts the CPU to sleep when there's nothing to do.

Regards, Peter

[Mac4]

My motherboard came with Via Hardware Monitor v 2.05 and it changes drasticaly too. When I watch it in Bios almost no change about 35C, but in Via it changes every 5 secs. From 35c to 42c and then back. I think it could be a problem with the monitoring prog and my drivers.

[Kuasimodem]

When I first put my system together, the processor would idle at about 40C and go to about 58 at 100%. After letting it run all night just running a 3D screen saver, I let it idle down and the temp dropped to 35C at idle.

I next ran Sandra2001 "burn in" utility for about 2hours.

Right now my processor is sitting at 25C with a case temp of 22C, under full load I rarely see temps over 42 degrees.

Abit KT7-RAID
900 T-bird (Super Orb)
3 case fans (all drawing out back) in Antec KS282+ midtower case.