Perhaps unevenly applied thermal paste? Man, that's still a big difference... let us know what you find out. Never read a post like this before (not that I've read EVERY post)
I'm wandering if the temp reader on CPU may be damaged, core 1 drops in temp very rapid after load, like in a 10th of a second, where as core 0 cools over a few seconds, any way to test? can anyone recomend an after market temp guage for CPU?
Have you checked with a razor blade to see if the mating surface of the heatsink is actually flat? If it's not, then the CPU won't be evenly cooled even if the thermal gunk appears to be squished properly.
I bought the low profile arctic cooling HSF recently, and when it arrived it quite badly needed lapping to make it flat (i knew there was a good chance it would need it thanks to frostytech) but once it was done, the temps settled down on my 6000+ and it was then actually able to run orthos for more than 3 minutes (12 hour stable ... good enough for me)
I'm using a Scythe Mini Ninja with Arctic Cooling MX-2 thermal paste on an AMD Athlon 64 X2 6400+ (Windsor). CoreTemp and SIW are both showing a 5-6 degree difference between my core 0 and core 1 temp. At idle core 0 is 37 and core 1 is 31.
Is this due to unevenly applied thermal paste? Or is the heatsink not installed flat?
sounds like your heatsink is on crooked. would make the most sense. double check your setup.
To test: clean HSF & CPU completely of all thermal compound. apply a tiny amount of compound to the HSF only. Spread it evenly. wafer thin amount, just enough to stick to another surface to visibly see that they have made contact. Re-mount your HSF to your CPU, then take it back off. Check to see if the thermal paste that touched the CPU is evenly distributed. If it is. then.. thats not your problem and it sounds like its a problem with the CPU sensors IMO. Rma it. or if your lucky enough to have another dual core CPU on hand, test it in your system.
Old thread I know, but fwiw I have a similar situation with dual E5472 quad-core Xeons in an Asus DSEB-DG motherboard. Core temps according to SpeedFan 4.37 show a similar 10C variation pattern on both CPUs:
Core 0 50C
Core 1 60C
Core 2 43C
Core 3 43C
Core 4 38C
Core 5 48C
Core 6 44C
Core 7 48C
Using SIW, core temperatures also show the same pattern but are all exactly 5C lower than SpeedFan.
The temperature readings for my graphics card and four RAM sticks are identical however between SpeedFan and SIW.
After seeing this thread and also looking at an Intel document on the physical quadcore chip layout (the core centers are in-line and quite close to each other), it weems unlikely that this is a thermal paste/heat sink issue.
If anyone out there has more insight regarding the interpretation of these readings please let us know. I don't like the 60C reading considering that the Tcase (not core temp) max specification is 67C. It looks like instrumentation error so I'm not too worried though.
I have an Intel E8500 Dual Core and the same problem, with two different coolers. The stock one and an Arctic Cooling ALPINE 7. With Core Temp, there are huge differences between cores, for example:
Idle
Core 0 - 50 C - 0%
Core 1 - 32 C (varying from 32 to 44 degrees) - 0%
Load
Core 0 - 58 C - 100%
Core 1 - 58 C - 100%
I've tested it using Prime 95 and the difference appears only in idle. As soon as it starts to work, temperatures even up, but at idle, there's a problem. Do you think you can help me?
Your sensor is bottoming out or "sticking". It's not actually running at 50C at idle, the sensor simply doesn't respond below 50C. Nuff said in an old thread.