Stuck CPU temp sensor or what?

[aka_GK]

Hi!

I assembled test loop on the table to overclock the CPU and faced strange thing.
My loop order is: TC PA140.3 + Yates @1100rpm -> EK Res -> DDC1T pump -> Watercool Heatkiller Rev. 3



But take a look at this:
This one is made at 27°C ambient, coretemp and realtemp show 38/36°C Idle:


Second one is made at 20°C ambient - all temps such as NB, SB, Motherboard are obviously lower, but CPU is still at 38/36°C Idle:


Also if I increase rpms on the rad fans to 1500, CPU temps don't move lower than 38/36°C.
Under load temps go higher.
I am running Win7 build 7100.

So, is it something wrong with sensor? What can I do to fix this?

thanks in advance.

[Factotum]

say it here, unclewebb MAN

[Vinas]

What does your TJmax reading say in CoreTemp/Real Temp?

Also, if you underclock and/or undervolt your CPU what temps can you achieve?

Typically the loop should go Res -> Pump -> rad -> CPU but I doubt the way you have it setup is adding much heat load. Unless you have an iwaki pump or a ac120 pump that is direct drive, because those can add quite a bit of heat load. Still you would experience some temp fluctuations so... Maybe it is stuck? I had an e8400 that would never drop below 20c, even when the temp probe read -15c. So stuck sensors can happen although my hunch is that your TJmax is being read wrong.

[aka_GK]

say it here, unclewebb MAN

Is that an issue of realtemp?

What does your TJmax reading say in CoreTemp/Real Temp?

If saying about realtemp I guess it is set to 100c (it was by default in Settings -> Advanced Calibration Settings)
Is that right?

Also, if you underclock and/or undervolt your CPU what temps can you achieve?

Asus MB undervolts and lowers multiplier in auto mode, so it is running at 1.1v 333x6.0 as you can see in CPU-Z.
Temps stay 38/36c

Typically the loop should go Res -> Pump -> rad -> CPU but I doubt the way you have it setup is adding much heat load. Unless you have an iwaki pump or a ac120 pump that is direct drive, because those can add quite a bit of heat load. Still you would experience some temp fluctuations so... Maybe it is stuck? I had an e8400 that would never drop below 20c, even when the temp probe read -15c. So stuck sensors can happen although my hunch is that your TJmax is being read wrong.

yeah, this loop order is just for testing purposes. Anyway I can't believe that 7c drop in ambient temperature doesn't affect cores temperature

Everest shows TJmax as 105c

[rge]

Yes your core temp sensors are "stuck", most E8xxx series are in that they wont read below a certain amount, some wont read below 50C, some 40C, some 30C etc. But since you clearly dropped your ambients (per mb temps) and core temps did not go lower that pretty much shows it. both my E8400 and E8500 had some lower limit, as most E8xxx series do, worst I saw was a few "stuck" after reaching mid 50's. In fact if your E8xxx was not stuck at some temp, that would be unusual for that cpu.

No there is nothing you can do about it, although new i7 processors per intel are more accurate across whole range and do not bottom out like most E8xxx series core temps.

And tjmax for E8xxx series is 100C per intel, and that one is not in dispute. If you get a recent version of everest (you have a very old one) it will show tjmax 100.

[aka_GK]

rge
Thanks for the explanation, didn't ever heard about that before