C2D keeps spiking up 8-10C in temp [semi-resolved, case fan wasn't spinning up]

[yacoub]

Just noticed it today because SpeedFan keeps cranking my CPU fan up a bit and then right back down again. I was like wtf, so i popped up the chart and both cores are jumping around in their reported temps by as much as 8-10 degrees Celcius. Right up and right back down again. Really annoying. Not sure why this would suddenly start happening so I checked Task Manager and there's nothing running tasking the CPU, just me sitting here browsing sites on FireFox.

So i popped the cover off earlier to check for dust and whatnot. just noticed now that my rear case fan wasn't spinning. i was so interested in looking at the CPU fan i didn't even notice the case fan struggling and not spinning at times. (The little 3-way switch got set to the lowest speed which apparently wasn't enough power for it.)

Well that solves why the CPU fan was cranking up so much. Still not sure i like how much the CPU cores are jumping around in temp though but i guess that's normal.

 

[BonzaiDuck]

You're no exception to any of us here: nobody thinks it's important to add their fans to their configuration specs.

I have a Sanyo-Denki San-Ace 120x38mm 0.50+Amp exhaust fan ducted to the exhaust side of my CPU cooler. I tried using the CPU mobo fan-plug, then the "chassis" mobo fan-plug, and set the BIOS to enable ASUS' "Q-Fan." the San Ace wasn't spinning up from either of those two plugs (although the plugs easily power fans of lower amperage). But the remaining 5 mobo fan-plugs work fine with it, and can be set to vary speed with temperature.

If you are referring to a discrepancy in core temperatures, that's normal, but can be mitigated partially by lapping the IHS and HS base. But 10C variation in idle or load values for a single core? Or for TCASE alone?

I'd recommend using something other than SpeedFan to track your temperatures. What you describe is a behavior I noticed with SpeedFan running on a Prescott 3.4E processor.