990FX Extreme 4 CPU Temp Reads 40C in UEFI But Reads 10C in AMD Overdrive. Whaaa?

[Luke Cypert]

That's correct. AMD Overdrive (and Speccy) show my AMD FX 6300 idling a 10-14 degrees Celsius with the stock cooler. But when I'm in the UEFI on the hardware monitor page, it shows idle at 40-41 degrees Celsius.

In UEFI the Mainboard temp shows 36c. Speccy shows 37c for the Mainboard temp at idle. So does my CPU have a bad heat sensor?

Thanks!

[Luke Cypert]

I posted this on Overclock.net too: Help! CPU Too COLD! AMD FX 6300 Idles at 10c!!! 10 Degrees Celsius!!!!

Looks like my CPU is bad at sensing heat.

[- wardog -]

[/URL]Looks like my CPU is bad at sensing heat.

Why do you say that, especially after your reading 2advanced's post at OCN that is over 3hrs old.

He nailed it before I could respond.

[Luke Cypert]

Yes, looks like he explained it all :)

Thanks!

[- wardog -]

Mine just now.

[parsec]

wardog, you probably have seen occasionally people that think those low CPU temps on AMD CPUs are correct. Usually a little higher than yours, but still wrong.

All modern CPUs (including Intel of course) don't have temperature sensors like a thermometer that gives a temperature value. Intel's method is similar to AMD's, and any temperature displayed in a program is derived from data from the CPU, it is a calculation based on several pieces of data, some unique to the CPU. AMD and Intel did not intend the data that is used to display temperatures by various programs, to be used for that purpose at all. Its main purpose is to prevent the CPU from overheating and being damaged, as best it can.

Some Intel chipsets (Northbridge, Southbridge, etc) have a similar mechanism to check for overheating, but the lowest "temperature" that can be derived from their data is ~50C, that is the starting point. The detailed technical documents for the chips state that quite clearly. My Z77 chipset is like that, always reads 43C, except in summer with no AC on, then it goes up a bit. Some users thought they were hot, and put fans on them, or different heatsinks, but the temperature reading never went down, of course. A lesson in that for all of us.

[- wardog -]

Yea that's why this amalgamation of the data is to be considered a reference. And as to why it is not an exact reference either as it is influenced by many factors beyond reasonable control and manufacturing processes.

Still, the quasi-temp(reference data) compared between the OP and my pic is suitable for the purpose intended.

[parsec]

I agree, and was not implying otherwise, at least I thought so.

My point was we take CPU temperature readings as gospel, as the PC hardware reviews sites do, when in reality they are not that reliable, and not comparable between manufactures and even different models of CPU.

Temperature readings can be manipulated, as ASUS did with the BIOS of a board I have. After a BIOS update, the CPU idle temps went down ~10C, using their monitoring utility. I was getting sub-ambient temp CPU temperatures, at idle on an Intel system, which I have never seen before. Another monitoring program showed two CPU temperatures, the one ASUS changed to, and the one they previously used. CPU temps are the least accurate at idle/low temperatures, as we can see.

[- wardog -]

I agree, and was not implying otherwise, at least I thought so.

I didn't take it we disagreed. Quite the contrary, we're on the same page concerning temp readings/values.

I regards to bios revisions changing temps wildly, if I recall I saw that here too on one of the A8N-E's I ran.

[parsec]

Sounds good.

I missed that thread you mentioned.