# How can my CPU temp be 18° when room temp is 20°?



## RisingSun

Both SpeedFan and HW Monitor Pro report that my four cores idle around 16-19° and under load are in the low 30's. How can this be? My room temp is probably 20-22°. My BIOS reports CPU idle temp at around 40°. What are the real temps of my CPU cores?


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## powerpack

Trust BIOS. Why the applications are incorrect I don't know.


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## CardboardSword

Apparently the temperature sensors on an awful lot of AMD aren't actually on the cores or something? So the reading given is actually a lot cooler than what the cores are. I've got the same problem. with my 1055T. Idle temps for me are about the same (18-19 degrees celsius) in a room that's about 21*-22*. No idea why some readings are more accurate (Like the BIOS.). The best way to figure out how much its off by is to leave your computer in sleep mode, with your temperature program running. Leave it for a while and when you turn it back on, the low temperature should be that of room temperature. I've found mine is about 13* when I turn it on, meaning its about 8*c below what it should be. Yours may be the same or not, but give it a try. Just make sure you leave the computer long enough for it to cool properly.


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## Computer_Freak

remember, the temps showed on the programs is above ambient...

but 18 is still low.. so maybe its a faulty sensor...


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## jamesd1981

you could always try carefully placing a thermometer inside your case, and check it randomly a few times, at least it will give you an accurate measure of your in case temp !


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## Demilich

The bios is displaying the correct temperature.

Speed Fan will pull temp. out of of nowhere sometimes.

What is the name of the sensor that is reading 16-19 degrees celsius in Speed Fan? Most likely it's an ambient sensor thats incorrectly labeled with Speed Fan itself. It's most likely not a faulty sensor if the bios is closer to the realistic temp. of the CPU.

Try downloading CoreTemp. I get readings closer to the bios with CT than with Speed Fan.


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## RisingSun

Demilich said:


> What is the name of the sensor that is reading 16-19 degrees celsius in Speed Fan?



The sensor's name in SpeedFan is "Core" and in HW Monitor Pro it is "AMD Athlon II X4 640". 

I downloaded CoreTemp. Same readings.


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## Demilich

RisingSun said:


> The sensor's name in SpeedFan is "Core" and in HW Monitor Pro it is "AMD Athlon II X4 640".
> 
> I downloaded CoreTemp. Same readings.



Bummer. Just sounds like something isn't clicking with your operating system and the bios. If the bios says 40 degrees Celsius, then I would trust that reading. There's no way that your CPU is lower than 20 degrees Celsius.

What is the reading of the of the motherboard in the bios, and in Speed Fan?


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## RisingSun

Mobo BIOS: 28°

Mobo SpeedFan: 29°, 37°, 36°


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## Demilich

RisingSun said:


> Mobo BIOS: 28°
> 
> Mobo SpeedFan: 29°, 37°, 36°



That looks about right, I believe. I looked around on the Speed Fan website, and it did say that this issue happens occasionally. You may just have to deal with it.


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## FuryRosewood

if you know what it idles at in the bios, and what it idles at in speedfan, add a temp offset to the cpu value in speedfan.


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## RisingSun

Okay, here's what I did. I set an alarm in the BIOS to go off when my CPU hits 60°. I then lowered all my fan speeds and ran a bunch of programs until the alarm went off. My various temp programs showed anywhere from 46 to 50°. So my programs must be around 12° below actual temp.


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## Computer_Freak

check my sig for a good hardware monitor.

i find it to be extremely accurate.


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