cooling - CPU core temps suddenly spike despite low CPU load

23
2013-08
  • Eric

    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.

    Thanks!

    • Answers
  • Real Temp

    It sounds like your CPU heatsink / block is not properly attached or you are not using enough thermal paste.

    Does RealTemp report LOG in the Thermal Status area? That means your CPU has logged at least one thermal throttling episode. If it shows HOT, that means thermal throttling is fully engaged.

    How much thermal paste did you use and how did you apply it. You need to do this again.


    • Related Question

    intel - Safe temperature range for a Core 2 Quad CPU?
  • ThisTime

    Possible Duplicate:
    Does anyone know the temperature ranges one can expect on a core2 duo

    I've looked around for an answer to this for a while, and have found many conflicting answers. I've heard that it shouldn't be allowed to go higher than 45C or so, and I've also heard that 55C is a safe limit. I'd really appreciate some clarification.


    • Related Answers
  • William Hilsum

    It depends on the individual CPU, take a look at the Intel Core 2 Quad Specification site and click on your CPU to find out.

    It looks like average thermal specification is between 60c-70c, with some being higher

  • th3dude

    Usually anything in the 40-60 range is safe. If you hit the 60s or 70s you need to check your cooling solution. I believe most motherboards (double check yours) have a fail safe now where if your temp reaches a certain threshold, your system will power off.

  • Notorious Arab

    Anywhere from 25C to 55C is safe.

  • Canadian Luke

    It all depends on what you are doing on the computer.

    Example: Recoding a Blu-ray movie from 50GB to 25GB. In that case, the CPU reaches temperatures of 90C - 95C.

    You need strong fans to pull out the heat or the CPU may burn or system halts.