Question Is my cpu temp sensor broken?

[Xbonepcnovice]

Ok, very simple. Ive asked about this before but no one seemed to be able to help, but im going to ask again because its something that i can't seem to find a fix for
Specs
Ryzen 2400g (stock)(stockcooler)
16gb ram @3000mhz
Asus b350-k prime motherboard
Rx 580 8gb
Corsair cx500
2x1tb storage
1x480gb ssd boot drive

Ive updated the bios, it was a prebuilt from gladiatorpc but i installed the OS, no problems. And the motherboard drivers etc etc
My problem is my cpu fan will not scale with my cpu temp. Dosent matter how hot my cpu gets the cpu cooler will not speed up, it stays at the first stage of the fan curve. Bios temp shows - 100 cpu temp, obviously very very wrong. But every temp monitor software ive downloaded reads the same, 30c-40c idle. Program's ive used are
HWMonitor
Ryzen master
Speccy

Msiafterburner wont let me monitor cpu temps

All show the same temp
If i boot up Aisuite it shows the same temp as bios
Is there something i need to download, does my cpu have a faulty sensor? Any advice would be greatly appreciated. Ive had a look through the bios to see if theres any additional settings i can change, but there isn't anything i can change that would make a difference. I can't understand why my bios temp is horrendously wrong, but third party software is reading accurate.

 

[Mr.Spock]

any chance the 100 is in Farenheit vs Celsius?

 

[Xbonepcnovice]

any chance the 100 is in Farenheit vs Celsius?

Celsius

 

[InvalidError]

If the CPU fan does not track the CPU fan curve, the first thing I'd check is that the CPU fan is actually plugged into the CPU fan header instead of some other 4-pin fan header.

The BIOS and HW monitoring software use the same sensors, so if temperature monitoring works fine in Windows then the sensors should be fine. Try putting a heavy load on the CPU and see if temperatures shoot up. Sitting in BIOS puts one core under 100% load and the 100C in BIOS could be due to incorrect HSF installation.

 

[Xbonepcnovice]

If the CPU fan does not track the CPU fan curve, the first thing I'd check is that the CPU fan is actually plugged into the CPU fan header instead of some other 4-pin fan header.

The BIOS and HW monitoring software use the same sensors, so if temperature monitoring works fine in Windows then the sensors should be fine. Try putting a heavy load on the CPU and see if temperatures shoot up. Sitting in BIOS puts one core under 100% load and the 100C in BIOS could be due to incorrect HSF installation.

Thanks, ive monitored the temps using hwmonitor on another screen with a 2 screen setup, it does heat up with load while gaming and benchmarking. I'll check to see if the fan header is plugged in to the correct connection. What is HSF installation? Bios is negative 100c, not sure if i stated that in my original post.

 

[InvalidError]

What is HSF installation? Bios is negative 100c, not sure if i stated that in my original post.

HSF = heatsink-fan. If temperatures under load in Windows look reasonable, then the HSF install is good enough.

Since there was a space between '-' and 100 in your initial post, it was unclear if that was meant to be part of the number of just a random thing. Negative readings in BIOS when OS values look reasonable mean either the BIOS isn't reading the correct values, the values it is reading are getting out of bounds under BIOS conditions or the BIOS has a temperature monitoring bug.

 

[Xbonepcnovice]

HSF = heatsink-fan. If temperatures under load in Windows look reasonable, then the HSF install is good enough.

Since there was a space between '-' and 100 in your initial post, it was unclear if that was meant to be part of the number of just a random thing. Negative readings in BIOS when OS values look reasonable mean either the BIOS isn't reading the correct values, the values it is reading are getting out of bounds under BIOS conditions or the BIOS has a temperature monitoring bug.

Any advice? Im guessing a bios update maybe, i did update it when i was trying to solve the problem. Worth updating again?

 

[InvalidError]

Any advice? Im guessing a bios update maybe, i did update it when i was trying to solve the problem. Worth updating again?

If you are already running the latest BIOS available for your board, updating again is unlikely to make any difference.

Anoter possible cause is that on-chip temperature monitoring can be highly temperamental at temperatures under 30C as diode junctions can be horribly non-linear at temperatures below 40C or so. You may just have gotten a chip that is at the worse end of the scale. You could disconnect the CPU fan, go into BIOS and see if the temperature goes from impossible to plausible after a few minutes as the chip warms up to confirm that.

 

[Xbonepcnovice]

If you are already running the latest BIOS available for your board, updating again is unlikely to make any difference.

Anoter possible cause is that on-chip temperature monitoring can be highly temperamental at temperatures under 30C as diode junctions can be horribly non-linear at temperatures below 40C or so. You may just have gotten a chip that is at the worse end of the scale. You could disconnect the CPU fan, go into BIOS and see if the temperature goes from impossible to plausible after a few minutes as the chip warms up to confirm that.

Ok, so the reason the cpu fan speed isn't scaling with the cpu temp is because the bios temperature is entirely wrong?

 

[InvalidError]

Ok, so the reason the cpu fan speed isn't scaling with the cpu temp is because the bios temperature is entirely wrong?

Once the PC is booted, the BIOS isn't involved anymore.

Have you checked that the CPU fan is indeed plugged into the appropriate CPU fan motherboard header yet? Can't control the CPU fan if it is plugged into a case fan or pump header instead.

 

[Xbonepcnovice]

Once the PC is booted, the BIOS isn't involved anymore.

Have you checked that the CPU fan is indeed plugged into the appropriate CPU fan motherboard header yet? Can't control the CPU fan if it is plugged into a case fan or pump header instead.

No, but i will. I can't do it right know but I'll try what you suggested when i get a chance. Thank you for replying.