Intel C2D CoreTemp/TAT/Everest and motherboard reported temp = fact and reliable!!!

str · 8 Sep 2007 at 22:42

I've been reading about C2D temps after disbelieving the high temps reported by TAT/CoreTemp/Everest for my E2160 and what I've read is very interesting!

There are three temperature sensors in a Core2Duo CPU. The first one is situated between the two cores and is closest to the IHS and the other two are in the hottest part of the CPU cores.

The first sensor is known as the Tcase temperature sensor and is actually the CPU temperature reported by the motherboard as seen in the BIOS or Asus Probe or whatever. :eek:

The other two sensors are known as the Tjunction temperature sensors which is what we see in TAT/CoreTemp/Everest.

The hottest Tjunction temp (hottest core temp in TAT/CoreTemp/Everest) is generally ~15c (+/- 3c) HIGHER than the Tcase temp (CPU temp reported by the motherboard).

The Tjunction value reported in CoreTemp (85c or 100c) is actually the maximum Tjunction temperature a C2D CPU should be able to reach before SHUTDOWN occurs.

Here is a table showing the range of temps you might experience:

-Tcase (as seen in the motherboard BIOS etc)/Tjunction (as seen in TAT/CoreTemp/Everest)-

--60--/--75--75-- Hot
--55--/--70--70-- Warm
--50--/--65--65-- N
--45--/--60--60-- O
--40--/--55--55-- R
--35--/--50--50-- M
--30--/--45--45-- A
--25--/--40--40-- L
--20--/--35--35-- Cool

You can read all about it in great detail in this post by CompuTronix over at Tom's Hardware.

Obviously there are issues which can cause confusion (see CompuTronix's thread about offsets etc) but the basis of it is scientific and it can be used to eliminate doubts about C2D temp reporting. :cool:

ns400r · 9 Sep 2007 at 01:29

Yep, I posted the same link a while back but people rarely seem to look at old posts or search for such info. Interesting though.

http://forums.overclockers.co.uk/showthread.php?t=17755255

WJA96 · 9 Sep 2007 at 08:29

This has been posted several times before, but it's not a bad thing to repost it. Sadly a lot of 'experts' are ex-AMD owners and are freaked out severely by temperatures over 55C whereas anyone who owned a Prescott takes temperatures in the mid-70's in their stride. Intel have built in major safety features into their CPUs to prevent them being damaged by ham-fisted installers or reckless overclockers like us and the chips are perfectly stable, even at very, very high temperatures.

str · 9 Sep 2007 at 11:18

Yeah.

I've been using AMD CPUs for a long time and I knew exactly how to achieve a cool running CPU and a cool running case with virtual silence. The big temp difference with my E2160 setup did freak me out although I'm comfortable with it now.

After a steep learning curve I now have my setup running "reasonably" cool with virtual silence (northbridge heatsink still runs a little hot) and having experienced the top end high temperatures I definately appreciate those safety features. The CPU is still working perfectly even after severe temperature and vcore abuse so I can attest to how durable my Core 2 Duo CPU turned out to be at least for now anyway.

Here's a screenshot after 24 hours of Orthos at 3GHz (333 x 9 with 1.375v):

The temps reported by TAT/CoreTemp/Everest are reasonably consistent with each other and also the delta between motherboard reported CPU temp (Tcase) and the core temps (Tjunction) is ~15c just like was explained by CompuTronix.

My next task is to lap the E2160 IHS and the Tuniq Tower's contact plate and hopefully the temps will drop a few degrees once I've done that.