Why is my E4300 hotter after changing only motherboard ?

[techeee]

Hi all,

I was using the E4300 + ECS P4M800PRO-M motherboard with
no OC changes except the BSEL1-VSS pin mod done to E4300
(http://www.ocforums.com/showthread.php?t=498167)

The cpu runs at 2.4GHz and
the temperature reported (ubuntu Sensors-applet) was cool at 30 deg C
with the stock Intel cpu fan.

Recently I changed just the motherboard to ECS 945GCT-M/1333
- nothing else changed - and find cpu temp reported now is 40 deg C.

First, I let the old intel thermal paste be on cpu/fan as is and saw 40degC.
Then scraped the paste off fully from cpu/fan and used a fresh coat
of Antec silicone grease (http://shop3.frys.com/product/4764099)
and temp reported is still 40degC.

Any ideas on why the same CPU will report 10 degree higher
with only motherboard change ?

More importantly, gurus :
1. which motherboard temp report is right - P4M800PRO-M or 945GCT-M ?
2. How do I confirm?
3. Should I install windows just for cpu-z tool to check temperature?
4. Are there any other tools on ubuntu I should be using to confirm temp ?

Any insight is greatly appreciated !

 

[myocardia]

techeee, welcome to anandtech. How well did you clean off the top of the IHS (CPU), and the bottom of the heatsink? If you cleaned them, and didn't use very much AS5 when you reinstalled the heatsink, then that's all you can do. Since the BIOS isn't reading your core temps, it all boils down to how accurate the sensor is being "sensed", if you understand what I'm saying. I've seen much different temps from one motherboard to the next, in the past. I've even seen a BIOS update change the temp readings, on the same board.

 

[Duvie]

Also pay attention to actual vcore being delivered...This can greatly differ from boards...I can set default 1.325v on my Asus board and come into windows at 1.24v and then under load drop to 1.2v....I have to set it to 1.45v in bios to run stock vcore under load. It come into windows at 1.36v after setting it to 1.45v....

on the other hand the chip in my FDFI board doesn't nearly have as much droop or undervolting....

So pay attention as voltage is a big factor in heat..

 

[betasub]

Many possible reasons - including the good suggestions above -
Cooling: HSF, TIM, BIOS fan control, socket air flow, adjacent chipset heatpipes etc.
Voltage regulation: VCore in BIOS, actual VCore (over/undervolting)
Temperature sensor: usually taken from a BIOS reading of the CPU sensor, different Tjunction values (Tjmax).

As myocardia says, a lot depends on the BIOS. Different BIOS may give different reading, even on an otherwise unchanged set-up.

 

[THUGSROOK]

Originally posted by: Duvie
Also pay attention to actual vcore being delivered...This can greatly differ from boards...I can set default 1.325v on my Asus board and come into windows at 1.24v and then under load drop to 1.2v....I have to set it to 1.45v in bios to run stock vcore under load. It come into windows at 1.36v after setting it to 1.45v....

yet you still bought an Asus