CPU temp lower than ambient?

Forum CPU & Components : CPUs CPU temp lower than ambient?

Hi, I recently had a problem with my motherboard and RMA'd it for a new one. So the new one came, and I didn't have new thermal paste so I had to put the CPU cooler back on with dried out paste. I had temperatures idle at 50-60c and Prime95 go over 99c. Playing a game like League of Legends went up to as much as 92c. So I cleaned out all the thermal paste and just left it clean. It idled at 40 but still went over 90c on Prime95. I decided I would get a new cooler and thermal paste. I decided on Artic Silver AA and the Coolermaster Hyper 212 Evo. After installing the new cooler and new paste, I'm getting temperature readings of as low as 14c. My thermostats for the house says the ambient is at least 20c. What is the problem? How is it possible that my CPU temp is 6c below ambient?

The programs I'm using are Core Temp and Speedfan.
I'm using an MSI P55M-GD41 Motherboard with an i7 860.

Reply to sk718

Geez!!! Uhm NEVER run a PC on old paste or without any. The I7 860 has a max of 72.7degrees.

http://ark.intel.com/products/4131 [...] -2_80-GHz)

I think you did some serious damage there. It will never perform as it should again.

------------------------------ Computers don't work, there are just degrees of not working.
Reply to Novuake

Any modern CPU has no problem running at 90c for a short amount of time man. Any current CPU will slow down after 99c to avoid damaging itself. And no, it still perform very well.

Message quoted 1 times

Reply to sk718

make sure you get new thermal paste before using your computer again....

------------------------------ Nap time!-amdfangirl
Reply to amuffin

read my post again, I already have the new thermal paste. I want to know why I am getting temp reading lower than my ambient.

Reply to sk718

sk718 wrote :

Any modern CPU has no problem running at 90c for a short amount of time man. Any current CPU will slow down after 99c to avoid damaging itself. And no, it still perform very well.

You ask advice then you argue with people who work with these things on a daily basis?

Message quoted 2 times

------------------------------ Computers don't work, there are just degrees of not working.
Reply to Novuake

Novuake wrote :

You ask advice then you argue with people who work with these things on a daily basis?

Maybe you should read my whole post instead of the first line and replying something that has nothing to do with my problem.

Message quoted 1 times

Reply to sk718

sk718 wrote :

Maybe you should read my whole post instead of the first line and replying something that has nothing to do with my problem.

Your problem is a damages chip/motherboard. You can not expect reliable temp readings from damaged parts.
Inaccurate temps are the first signs of trouble.

Message quoted 2 times

------------------------------ Computers don't work, there are just degrees of not working.
Reply to Novuake

http://www.cpuid.com/softwares/hwmonitor.html

Run this and see what you get.

Its the full load temperature that you should be worried about, although I have read a few postings about i7 have broken sensors, you could RMA to Intel, but don't tell them about running without heat paste or they will void RMA.

------------------------------ HP Pavilion DV7-3020EA Entertainment Notebook PC + Win 7 Pro SP1 x64
GA-870A-UD3 + AMD PH-II X6 1100T BE + Hyper212+ + 8GB DDR3-1600 + GTX460 + Win 7 Pro SP1 x64
GA-870A-UD3 + AMD PH-II X4 840 + 4GB DDR3-1333 + ATI 3450 + SVR08 R2 SP1 x64
Reply to das_stig

You new thermal compound must be magic. :bounce:

Message edited by jsc on 12-29-2011 at 03:43:25 PM

Reply to jsc

Thank you. Some backup...

------------------------------ Computers don't work, there are just degrees of not working.
Reply to Novuake

i done the same to my old athlon and it popped with an almighty bang.

I am suprised it still works TBH. Very Lucky.

Get it checked via some apps as described above. You might just be ok.

------------------------------ Gigabyte GA-MA770-UD3 rev 2.0 / AMD Phenom II X4 965 OC @ 3.8 GHz / Hyper 212 Evo / 4 x A-Data 2GB DDR2 unbuffered SDRAM - 800MHZ
Sparkle Nvidia 9800 GT 1024MB / Soundblaster Audigy 4 / OCZ Vertex 2 SSD running Windows 7 Ultimate 64bit
Reply to deejayburnout

Novuake wrote :

Your problem is a damages chip/motherboard. You can not expect reliable temp readings from damaged parts.
Inaccurate temps are the first signs of trouble.

I'm 100% sure there is nothing damaged. Idle CPU voltage is 0.89 while full load is 1.18.

Min temp is 14c after overnight idle, Max temp is 53c on Prime95

Reply to sk718

With modern thermal regulation and speed step the computer can do 2 things to control temp. It can back down the FSB and Multiplier and the VRM can back down the v-core. I think its extremely unlikely that you did any damage, however when it comes to computers anything is possible.

More likely Core temp is wacked out and not reading correctly or the onchip temperature sensor is defective.

Check the temp in the mother board bios. It should idle around room temp while in the bios cause it is not doing any work. If it is lower than room temp the sensor or bios is wacked. You can try update the mobo bios. If the temp seems normal here then try hwmonitor in windows.

If the CPU sensor is defective best bet is to just live with it. Core temp should show you the temp of all 4 cores. Its unlikely that all 4 sensors are wacked so go by the highest one.

Reply to bucknutty

Novuake wrote :

Your problem is a damages chip/motherboard. You can not expect reliable temp readings from damaged parts.
Inaccurate temps are the first signs of trouble.

Novuake wrote :

You ask advice then you argue with people who work with these things on a daily basis?

You can’t be sure of anything in situations like this. Your comment is awfully arrogant. One thing I have learned in my 15 years of building and supporting PCs is anything is possible, and just when you are sure you know what the problem is something impossible happens to prove you wrong.

That said there is a pretty good chance that board and or chip messed up, but I would bet its fine.

Message edited by bucknutty on 12-29-2011 at 08:11:47 PM

Reply to bucknutty

cpu sensors have trouble detecting low temperatures, the lower the temperature, the less accurate they are. Go by the full load temp, disregard the idle temp if its that low. Something to try would be to update your motherboard BIOS with the latest from your manufacturers website. This can often fix temp monitoring issues. Even just hard resetting the bios to factory defaults can fix odd issues like this. I've seen cpu's report 128C and flashed to new bios and it was fine. Have had fans running at max speed, no matter what settings, hard reset the BIOS, fixed. So try that, it might/might not work, but its worth a try.

------------------------------ INTEL CORE 2 Q6600 @ 3.49GHz, CM Hyper TX3, ASUS P5N-D, 8GB DDR800 RAM, Powercolour HD6850, 650w Antec Trupower New PSU
Reply to iam2thecrowe