[Solved] Odd temperature differences in different applications

Valantar

Golden Member
Aug 26, 2014
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I'm running my old Q9450 at a decent overclock (3.2GHz, up from 2.66). It's supremely stable, and has been so for quite a while - I actually run stably at higher frequencies now than I could a couple of years ago, without changing anything with regards to cooling or other factors. The CPU is OCd through the motherboard's "CPU Level up" function, which as far as I can tell has changed the FSB speed and little else (CPU-Z reports core voltage at 1.238V, and reading around I've found that stock voltage should be 1.3V).

The thing is, temperatures seem a bit high. I use Pulseway to remotely monitor temperatures and loads on this computer as well as my file server/HTPC, and it reports cores 0 and 1 at ~58 degrees C at idle, cores 2 and 3 at ~65 degrees. Running any kind of stress test, this doesn't increase more than a few degrees - cores 0 and 1 might reach 65, while 3 and 4 stop at 68-69. I haven't really thought about this before now, as those temperatures don't strike me as very high, at least not under load (even if the uneven temps lead me to think the TIM might be unevenly distributed). So I got a bit of a shock when I looked at the ark.intel.com listing for the CPU and saw its tCASE listed as just 71.4 degrees. Now I know that core temperature and tCASE are not the same, but that's still a bit frightening. Checking with Asus's "AI Suite" (motherboard software), idle temps are around 35-40 degrees, which matches reviews from when the CPU was released. So, am I simply seeing a large but normal gap between core and heatspreader temperature, or might there be something wrong here?
 
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sm625

Diamond Member
May 6, 2011
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A 4 Deg C gap between hottest and coldest core is normal.
 

ShintaiDK

Lifer
Apr 22, 2012
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tCase is a temperature you dont measure. It requires an external thermal probe between the CPU and the heatsink.

So the tCase at ark.intel.com is completely useless information for you. Tjmax is the only temperature limit you need to know and you measure tjunction to reach there.

Your temps are perfectly fine and normal. tjmax is around 100C.

C2Qexploded.jpg
 
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Valantar

Golden Member
Aug 26, 2014
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A 4 Deg C gap between hottest and coldest core is normal.

That's not what I'm asking about - my concern is the fact that most applications report idle CPU temps of 60-65 degrees, while Asus' own application reports temperatures in the 35-40 degree range. Either one of them is pretty far off, or they're looking at completely different sensors, which I find pretty confusing.

ShintaiDK: Yeah, I know that no sensors measure tCASE, I just got a bit freaked out since that's the only temperature listed in the processor spec. Seems like Intel didn't start listing tJUNCTION until later (or maybe that's only for laptop CPUs?). Any way, after reading up on it it seems like tCASE is specified as maximum temperature under normal operating conditions with the stock cooler, and says nothing about safety. In other words, nothing to worry about, and now I'm actually quite pleased that I'm staying around that temperature even with a 20% overclock and a rather cheap air cooler.




Update: I've tried looking into this a bit more now, and HWMonitor lists core temps in the same range as I've said, while the CPUTIN sensor (motherboard CPU temp sensor) reports 35-37 degrees at idle. After running OCCT for 20 minutes, core temps have stabilized at around 77-79 degrees, while CPUTIN is around 62-65. In other words, I'm well within safe temperatures, and the 20 degree delta between apps was due to different sensors being reported. I guess the high idle core temps just show how big strides Intel has made in idle power conservation in recent years.
 

ShintaiDK

Lifer
Apr 22, 2012
20,378
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Did you disable Speedstep/EIST etc? That may explain your high idle temps. If so, enable it again. It serves no purpose to disable.

Whats your idle frequency?

ark.intel.com is an OEM portal. Thats why enduser information isnt listed as such directly. tCase is only useful if you are designing a cooler.

tCase is measured externally. Not by any software tool you got. So you cant use tCase information for anything.

If you want to measure tCase this is how you do it.

20101130021523.png

20101130022009.png


Also a good example here:
http://www.xtremesystems.org/forums...r-Intel-Core-processors&p=3717181#post3717181

Using stock cooler in that test, the tCase reaches 71.7C when the CPU hits 98C.
 
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Valantar

Golden Member
Aug 26, 2014
1,792
508
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Did you disable Speedstep/EIST etc? That may explain your high idle temps. If so, enable it again. It serves no purpose to disable.

Whats your idle frequency?

ark.intel.com is an OEM portal. Thats why enduser information isnt listed as such directly. tCase is only useful if you are designing a cooler.

tCase is measured externally. Not by any software tool you got. So you cant use tCase information for anything.

I understand that you need an external sensor to measure tCASE and that it doesn't really relate to any thermal specs of the cpu, sorry if that didn't come across in my previous post.

As far as I know, Speedstep settings have never been touched. The CPU idles at 2.4 GHz (multiplier drops to 6 from 8). CPU-Z lists the multiplier as 6-8, so i guess that's as far as it scales. At stock clocks that would mean idle clocks of 2GHz (down from 2.66).