CPU reportedly running at 255 C causing slowdown

[X3no]

So I have an AMD Phenom II X6 1100T which is supposed to be clocked at 3.30 GHz. However I recently noticed that my pc started to run really slow. I check the task manager and it reported my CPU clock speed at 0.76 GHz. This makes my PC really slow and unstable.

I checked my power settings to make sure that it was on high performance and that the minimum clock speed is at 100%. Then I decided it may be a temperature issue so I installed speedfan and checked the core temp. This is where I get lost, speedfan is reporting my core temp at 255 C this is obviously unreasonably high and when i place my hand near the cpu fan the air is barely above room temp. All the other temps are normal. So I'm assuming that something is wrong with the core temp monitor which is causing the cpu to be clocked down to try and stop it from overheating even though it is fine.

I tried restarting my pc to fix the issue and the cpu temp started out at around 50 C then after about 30 minutes when it reached ~60 C it jumped straight up to 255 C.

What can I do to fix this?

Though it may not be ideal, is there a way I can stop the cpu from being clocked down when it gets too hot?
I have stuff I need to get done tomorrow and would like to be able at least get my PC into a usable state.

Thanks in advance for any help.

Specs:
CPU: AMD Phenom II X6 1100T
Motherboard: MSI 970A-G45 AM3+ AMD 970
GPU: Nvidia GTX 560Ti
RAM: 8GB(2x4GB) DDR3 1866
OS: Windows 8 Pro x64

 

[rds1220]

Well it's definitly not running at 255 degree's celcius thats 491 degree's F. If it was that hot the motherboard would probably be melting. Down load CPU-z and HWmonitor and see what it says.

 

[X3no]

CPU-z reports similar slow speeds and HWmonitor reports the same temperature of 255 C.

 

[cmcghee358]

That's a known issue with the 45nm architecture. No, it's not really at 255C, it's a bad probe/reading.

But the throttling is interesting, what are your other Core readings?

 

[X3no]

That's a known issue with the 45nm architecture. No, it's not really at 255C, it's a bad probe/reading.

But the throttling is interesting, what are your other Core readings?

Here is a screenshot of all the readings

http://i.imgur.com/d9sAfh.png

The drop in cpu usage aligns with the speed decrease/temperature reading error.

 

[payturr]

Oh boy that doesn't look good. What heatsink you have on the chip? Thermal paste?

 

[koreanzombie]

lol holy ****, thought the CPU would instantly shut down past that mark.

 

[seriux]

*** what you have there is a chip you can overclock to what ever you want... you know she wont fry 😉

 

[gamerk316]

Out of curiosity, what does the temp read from the BIOS? If the temp is high, what does the default clockspeed indicate?

You may have to disable thermal throttling if the temp sensor went. Best bet may be to RMA the CPU in this case.

 

[koreanzombie]

*** what you have there is a chip you can overclock to what ever you want... you know she wont fry 😉

ROFLLLLLLLL

 

[X3no]

I contacted AMD support and they said that

The Phenom II 1100T is supposed to cap out at 62C, so seeing readings of 255C after it passes 60C is likely the motherboard establishing that the CPU is beyond its maximum heat levels, and as such the CPU is ramped down to minimal levels to ensure that the CPU is not damaged due to excessive heat.

I still don't think it should work that way. How would I stop it from throttling? I looked in the bios settings and couldn't find anything.


I'm running the stock heatsink that came with the cpu and haven't touched it since it was installed.

 

[arthurh]

I would take a good long look at that HSF on your CPU and make sure it is still installed properly. Grab ahold of it and see if it moves easily, if it does then the clip on it came loose.

I know AMD makes a pretty good HSFU but have seen them come loose if PC was moved and banged into something. Depending on how it was mounted it could still appear to be attached but just be hanging there by one hold down clip.

Good luck to you at any rate.

 

[cmcghee358]

Yeah across all 4 cores, coupled with throttling is abnormal.

One my Athlon IIx3 425 it would show CPU1: 255C, but all my other cores were around 50ish.

I'd definitely look at RMAing the chip, which I dread because I imagine the return policies on chips to be awful

 

[cmcghee358]

Also on your HWMonitor screen shot, your vCore shows it topped out at 1.544. Thats a bit on the high side. Manually set your vCore to 1.3 and then check your temps in BIOS.

 

[459pm]

I have the same problem. =[