CPU Temp rise after bios flash

orion446

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Sep 6, 2004
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Flashed bios and cpu idle jumped from 37c to 48c when system was rebooted. Cpu is 2.4 P4 (800mhz) HSF is Zalman CNPS7000 alcu w/ AS5. What is going on ?
 

Navid

Diamond Member
Jul 26, 2004
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How are you measuring the temperature.
It is better to use a utility in Windows like Motherboard Monitor for that.
When in Bios, the CPU gets hotter than it does when idling in Windows.
 

orion446

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Sep 6, 2004
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I am using the MSI utility Core Center and right now it is reading an idle temp of 48c and a system of 32. Why would the temps change after a bios flash?
 

TripperJoe

Senior member
Mar 15, 2001
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flash back and see if it changes back.

are the voltages/clocks the same? all the fans spinning at the same speed?
 

Navid

Diamond Member
Jul 26, 2004
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Originally posted by: orion446
Why would the temps change after a bios flash?

They should not.
Unless, it has automated temperature control that controls the fan RPM and flashing the Bios, changed that scheme.

What might have happened is that something changed at the same time that you flashed and has nothng to do with the flash itself. So, as suggested, if you flash back, you may find out that the temps are still high. So, it is a good idea to try that and flash back.
 

orion446

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Sep 6, 2004
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I flashed back and the the idle temp is now 42c , I also removed the HSF and reapplied AS5 so maybe after the AS5 settles down the temp will return to the way it was. There are four temp probes placed in different locations inside the case, The highest temp reading 26c. Why is the temp reading from MBM5 higher than the temp probes? All the voltages/clocks remained the same after the flash
 

Navid

Diamond Member
Jul 26, 2004
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Originally posted by: orion446
Why is the temp reading from MBM5 higher than the temp probes?

Because, the probes measure the temperature on the chip.
Motherboard monitor measures the temperature of the die (semiconductor).

I attempt to explain this here.
There is a semiconductor component (a diode) on the CPU, which provides a voltage that is dependent on temperature. This voltage is given to a sensor that converts the voltage to a digital number representing the temperature. This is what Motherboard Monitor or any other software utility shows. This is the hottest temperature on the CPU.

There is a thermal gradient in the CPU chip. The die is inside the plastic package (the chip). The die is the hottest part of the package. The die passes its heat to the plastic package. The plastic package passes its heat to the heat sink. The probe measures the temperture of the plastic, which is lower than the temperature of the die. There is even a thermal gradient in the plastic itself. The plastic right near the die is hotter than the outer surface of the plastic, which the probe has access to.
 

xbassman

Golden Member
Feb 25, 2001
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Originally posted by: orion446
I am using the MSI utility Core Center and right now it is reading an idle temp of 48c and a system of 32. Why would the temps change after a bios flash?

I think everybody is missing the mark here.......
You bios is attempting to accurately report the signal it is getting from your mobo sensor.
It appears that they changed how temp is reported with your new update. Your temps are not higher, your bios is just reporting the temp with the new adjustments that they made.

You might read the changelog of your new bios or check MSI's website.
MSI's Athlon 64 board has temp reporting problems also.

As to which temp is accurate? Who knows! The only way to know for sure is to run a thermistor yourself and have it hooked up to an accurate device.
 

Navid

Diamond Member
Jul 26, 2004
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Originally posted by: xbassman
I think everybody is missing the mark here.......
You bios is attempting to accurately report the signal it is getting from your mobo sensor.
It appears that they changed how temp is reported with your new update. Your temps are not higher, your bios is just reporting the temp with the new adjustments that they made.

That is why I asked how he was measuring the temperatures wondering if he was relying on the temperatures reported in the bios. But, he said that he was using a utility in Windows. So, I don't think the bios upgrade can explain the change.
 

orion446

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Sep 6, 2004
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The temp reported with MBM5 is about the same as the bios and before the flash it was the same with the bios, MBM5 and MSI core center. I stopped using the MSI core center and stayed with MBM5, checked the bios reading and they remain the same. xbassman I think I understand what you are saying and I am going to place a temp sensor under the CPU to record and monitor the temps.
 

Degrador

Senior member
Jun 15, 2004
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Originally posted by: Navid
Originally posted by: xbassman
I think everybody is missing the mark here.......
You bios is attempting to accurately report the signal it is getting from your mobo sensor.
It appears that they changed how temp is reported with your new update. Your temps are not higher, your bios is just reporting the temp with the new adjustments that they made.

That is why I asked how he was measuring the temperatures wondering if he was relying on the temperatures reported in the bios. But, he said that he was using a utility in Windows. So, I don't think the bios upgrade can explain the change.

Yes, it can.

Ok, to pretty much extend what xbassman has already said:

The BIOS reads the resistance of the thermistor, and this translates to a temperature. However, manufacturers are often translating the reading into a temperature wrong. For instance, my P4P800 Deluxe says my cpu temp is currently 22C. There is no way possible for this to be accurate. The cpu is a P4 2.8C running at 3.2 - I have learnt that this mobo reports a temp approx 10C under the actual temp. I have a fan controller with temp probes, and with a temp probe just taped to the side of the cpu heat spreader, it reports 30C.

The reason a different BIOS will give different temps, is that the manufacturer (MSI in your case) has simply changed what the reading was in order to report the actual temp more accurately.

Don't worry - your cpu is not running any hotter. Just that the temp report has been altered. Also, Navid - MBM reports the temperature that is given by the BIOS - they're the same thing.
 

Navid

Diamond Member
Jul 26, 2004
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Originally posted by: xbassman
All the software utilities get the readings from the bios.

Thanks for pointing this out.
Do you happen to have any links for more reading on this?
I would like to learn more about it. Thanks!
 

orion446

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Sep 6, 2004
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Got the temp down to 41c CPU and 29c case, Plan on getting the Thermalright XP120 next week with a Panaflo 120mm L1A. I also replaced the 120mm fan in the top blowhole with a Panaflo H1A.