CoreTemp has a major Tjunction Max bug

[GigaByte]

Hello, I have a major bug report

After over 2 months with my new E4500 I just found out a week ago that my CPU indeed has 100c Tj Max and not 85c as CoreTemp (and even Speedfan) says.

A list of Tj Max 100c and 85c C2D's and how to tell your real temps can be found here: http://www.overclock.net/intel-cpus/263 ... ronix.html.

I verified this myself with my E4500 because we all know when you core temps reach the Tj max the CPU shuts down. Well I pushed my E4500 to 92c on the cores and it DID not shutdown, it didn't even thermal throttle (yes TM2 is enabled). When it reached 95c it started thermal throttling which occurs 5c below Tj max, so this verifies that CoreTemp is reading your core temps 15c too low to many C2D's out there.

Another bug is with "Tjunction" itself, it really should be mentioned as "Tjunction Max" as specified by Intel instead of just "Tjunction". Currently all L2, B3, M0 and G0 stepping C2D's are 100c Tj max and all B2 steppings are 85c Tj max. Correcting this bug would be very helpfull to those who are still confused as hell with this.

Last but not least, If you can add a temp reading for Tcase into CoreTemp that would be PERFECT. Tcase is measured at the geometric center on the topside of the processor integrated heat spreader. In many temp monitoring apps it is labled as "CPU". In Speedfan it could be labled as CPU, Temp, Temp1, Temp2 or Temp3. When we overclock and watch temps to make sure they are within spec it is the Tcase you look at, the cores themself basicly do not have a thermal spec, but common sense will tell you just keep the cores below thermal throttling temp (5c below your Tj max) or 5c below thermal throttle temp (10c below Tj max) for extra safety. Intel measures and creates a thermal spec based on Tcase, NOT THE CORES! Almost no one knows/understands this.

Thank you for reading, hope this clears up this almost unknown bug in CoreTemp

[GigaByte]

Nice, super friendly bump.

[GigaByte]

What...? Is this too complicated or something?

[imposter]

TheCoolest is cooking us some goodies thats why he hasn't replied yet. post up screen shots of speedfan + coretemp + your mobo's cpu monitor

[GigaByte]

Speedfan is showing the correct temps, after going through all the calibration proceedures I find out all I needed was to add +15c to the cores. Everything else is accurate, "TCase" is the "CPU" temp that all other temp monitoring programs will display, when Intel bases their thermal spec they base it on TCase. Cores are always higher than TCase, some CPUs have a Tj (Tj is your cores) to Tcase delta of 10c and some have a delta of 15c. This does not mean the difference between the 2 is always 10 or 15c, the 10c CPUs can exceed 16c difference and the 15c may exceed 21c difference depending on ambients, ammount of load and the CPU's vcore.

The exact delta can be perfectly seen by underclocking the CPU as much as possible with the lowest vcore you can run (>1.00v is best) and have the fan run at as fast as possible (even stock cooler can do this). Doing this will drop your Tcase temp to as much as 0.5c - 1c above your ambients, but it will NEVER drop BELOW ambients, and depending on your CPU your cores are to be 10c or 15c above what the Tcase is at. If the delta is a match (give or take +/-3c for flucuations) then you are calibrated.



Sorry if I am repeating myself, trying to make it as clear as possible. The guide link I posted explains it all (long read, but worth it trust me).

[The Coolest]

Sorry for the delay, I had a really long week.

Anyway, you're right. The Tjunction Max needs to be adjusted to 100C for all processors other than B2. There are some cases, however, where this adjustment just doesn't look right, temperature wise.
Regarding the "Tjunction" label. I'll see what I can do.
TCase reading is the standard CPU diode, I admit it's rather accurate in the latest generation of processors, but there is no standard to reading these. An application must support all known motherboards and I\O devices.
Using Core Temp you can compare temps on different motherboards with the same processor, while motherboard readings will probably differ, the CPU readings will not, as it's the same diode and same "measuring" mechanism that captures the reading.

[Retrolock]

Sorry to hijack thread TS

How about mine thecoolest?



How about this? Isnt this too low? My ambient temp is about 24-26c

[The Coolest]

Well I don't really know what to say here. Most likely bad callibration on the DTS or wrong tJunction...
What do other, more standard temperature monitoring programs say your CPU temp is?
Also is that load or idle?

[Retrolock]

Thanks for the quick reply thecoolest! That screenshot was taken during the night, and here's some shots i took right now during the afternoon. Temps are about much higher now, probably 32-34c

Idle:



Load



Is it really damaged? The DTS? This sucks

[Retrolock]

any inputs thecoolest?

[The Coolest]

This is strange, I thought I posted a reply to the thread a few days ago. Sorry for the delay.

I wouldn't say that the DTS is dead or anything. What could be happening is the DTS may not be perfectly calibrated and that's what's giving you the low temps. Also notice the CPU temp in everest, it's just 5C above what Core Temp reads. I don't think you have anything to worry about it.
Either way, as long as you stay 15-20C below the Tjunction, you're fine.

[Cheator]

I think the issue more applies to M0 steppings.

I am running CPUID's HWMonitor which reads my idle at around 38C and my load at around 67C. Coretemp reads it at about 15C and 55C.

So, I realize what you're saying TC, but is it fixable?

[The Coolest]

Yes, it's fixable.