Core CPU Temp shooting to 255°C

[NJWarrior12]

Hi,
About a month ago, I bought a new AMD FX-8350 8-Core Processor at 4.00GHz, and after installing it, I noticed that I was getting random FPS drops when playing any game. It would always drop from whatever value it was at (60 for BF4, 100+ for War Thunder), straight down to less than 30, and when playing games, this can get quite annoying. So a couple of weeks ago, I took my computer to my local PC repair store where they said that the inside was "filthy" and that the stock cooler was doing absolutely nothing and sounded like a jet taking off, so I payed for an Arctic Freezer 13 cooler. I took it home and started playing my games. The exact same problem persisted, so downloaded 2 CPU temperature monitors (SpeedFan and Core Temp 1.0) and looked at the core temps when the FPS drops occurred. Both said 255°C and after the episode, the temperature would drop back down to around 40°C.

Any help would be much appreciated.

My Specs:

CPU - AMD FX-8350 8-Core Processor 4.00GHz (with Arctic Freezer 13 cooler)
Power Supply - EZCool 650W Power Supply
GPU - GTX 660 GPU (2 GB RAM)
RAM - 8 GB DDR3
Motherboard - MSI 760GM-P21 (FX) (MS-7641)

 

[Supernova1138]

255 degrees is clearly a software error, and I wouldn't use Speedfan as it is known to have lots of issues like that with false readings. Try CPUID HWMonitor and see what reading it gives you.

Now your CPU cooler might not be the actual cause of your problems. There are two other distinct possibilities for why you're getting framerate drops. The first is your Power Supply, it's a low quality unit that can only actually deliver 430 Watts, and that's if it can actually deliver what its spec label says it can. Low quality power supplies can potentially cause performance issues as they tend to have trouble delivering consistent power when placed under heavier loads.

The other potential problem is your motherboard, you have a cheap, low end AMD motherboard with 4+1 Phase VRMs that have no coolers on them. That is not really sufficient to power an FX 8350, and the lower end AMD boards are known to have lots of issues with throttling the 8 core FX chips due to the VRMs overheating and being unable to keep up with the high power demands. You can use something like CPU-Z to monitor your clockspeed while playing, and if it is throttling back and you have ruled out your CPU overheating, your motherboard is a likely culprit.

 

[NJWarrior12]

255 degrees is clearly a software error, and I wouldn't use Speedfan as it is known to have lots of issues like that with false readings. Try CPUID HWMonitor and see what reading it gives you.

Now your CPU cooler might not be the actual cause of your problems. There are two other distinct possibilities for why you're getting framerate drops. The first is your Power Supply, it's a low quality unit that can only actually deliver 430 Watts, and that's if it can actually deliver what its spec label says it can. Low quality power supplies can potentially cause performance issues as they tend to have trouble delivering consistent power when placed under heavier loads.

The other potential problem is your motherboard, you have a cheap, low end AMD motherboard with 4+1 Phase VRMs that have no coolers on them. That is not really sufficient to power an FX 8350, and the lower end AMD boards are known to have lots of issues with throttling the 8 core FX chips due to the VRMs overheating and being unable to keep up with the high power demands. You can use something like CPU-Z to monitor your clockspeed while playing, and if it is throttling back and you have ruled out your CPU overheating, your motherboard is a likely culprit.

Hi,
Thanks for your reply,
I just used CPU-Z and played some World of Warships. As soon as my FPS dropped, I tabbed out and saw that instead of the 4099MHz it normally says, it said my clock speed was 1399MHz. In your opinion, do you think this is more to do with my motherboard or power supply? This is because I can't really afford to buy both a motherboard and a new supply.

Thanks once again.

Quick Update
I just had another look at CPU-Z and noticed that when my clock speed did drop, the voltage also dropped from around 1.3V to 0.8V.

 

[Supernova1138]

They both should be replaced at some point, but I would say the motherboard is the more likely culprit and would be the best immediate fix to the problem. Something like this is probably about the cheapest motherboard you should consider, boards cheaper than that are likely to have the same VRM setup you currently have.