CPU core temps suddenly spiking despite low load

My computer mysteriously shut itself down with no warning a few times over the past 24 hours, both at times when it was not being used but left on (incl. overnight) and a couple times when playing a game, so under at least moderate load.

This led to me installing a temp gauge (Realtemp 3.7) and a stress tester (prime95). The first run of the stress test showed a between-test phase idle temp of 79C but quickly pushed the cores to 105C at which point I stopped the test.

Then I opened up the tower and did a pretty thorough compressed air cleaning and made sure all the fans were spinning.

Oddly, all subsequent tests I ran didn't push the temp beyond 80C, and averaged around 40C. And for the next few hours, temperatures were just fine, including during gaming. Then just minutes after I left the computer alone, the fans kicked into high gear and when I checked the temp it was climbing over 90. I've copied a couple pieces of the log to illustrate (the temp's are in C; the far right column is CPU load %.

Here, while gaming:

19:56:15 3372.37 36 30 40 36 46.7

19:56:30 3342.44 36 33 40 39 53.1

19:56:45 3342.43 36 31 43 35 54.0

19:57:00 3332.46 37 34 41 39 60.2

And then later, just after stopping using the computer:

22:57:15 1596.39 87 86 87 89 3.2

22:57:30 1596.39 92 92 92 92 3.6

22:57:45 1596.39 88 88 89 89 3.4

22:58:00 1596.39 95 95 95 95 3.9

It seems like there's an obvious discongruity between load % and the CPU core temps. Could my cooling system just be sporadically failing?

Basic specs: Intel Core i5 3450 Quad 3.1 GHZ, 8gb DDR3, AMD Radeon HD 6850, CoolIT ECO A.L.C water cooling.

5 answers Last reply Best Answer
More about cpu core temps suddenly spiking low load
  1. check your cooling solution, it could be the water flow is stopped for a moment...

    causing the temp peaking, even without load..
  2. rdc85 said:
    check your cooling solution, it could be the water flow is stopped for a moment...

    causing the temp peaking, even without load..

    Is there a way to diagnose this? By sound, perhaps?

    And if this is the problem--water flow stopping--is the only solution to replace the unit?

  3. unfortunately, i'm not too fammiliar water cooling :D...

    I'll wait the other to fill in...
  4. Best answer
    I have a similar Corsair water cooler. The CPU block should have a fan power cord to operate the internal water pump. Use a fan monitor to check the RPM of the water pump. It should be running and consistent. My Corsair's pump normally runs around 4k RPM, I don't know what yours is nomally. If your water pump isnt working that is obviously a problem. If you have air in the lines, your pump will not be at a consistent RPM and you will have air locks where your pump occasionally stops pumping because it's getting stymied by air bubbles. In either case you will need to replace the entire cooling unit. Its a sealed system so fixing it will be excessively difficult.
  5. Thanks for this. Luckily the pre-built system still had 2 months left on the warranty, and after sending the details to the seller they quickly offered to replace the unit.

    So, out of curiosity, and since they're offering a different water-cooling unit as replacement, are there any warning signs one can look/listen for, other than heat spikes? The unit has, almost since I received it, made occasional gurgling noises. Does that always indicate air bubbles which should be there?
Ask a new question

Read More

Core Cooling Overheat CPUs