CPU not running at full speed while stress testing.

Hi lads!

I just got my PC to work! It's my first build, so i'm ever so happy!

My CPU is a E8400.
Anyhow, i downloaded some software, CPU-Z, Prime95 and CoreTemp.

And while running Prime95 i noticed that my CPU-Z recorded only around:
Core Speed 2671,5MHZ
multiplier set at x 8.0
rated FSB at 1333.6
Bus speed at 334.0mhz.
Volt at 1.192

Okay. I am aware of speedstep but since i'm stress testing it i assume that this will tell the CPU to work at full throttle! So what is the problem?

I havn't updated my Motherboard yet since i got it out of the box, could this have any influence?

I also have another quick question(s) :):
- how long should i be running prime95 (and which test would be suitable? (blend and so on)
- My temp wont raise above 49 while stress testing but my CPU heatsink is litteraly chillingly cold, i have to use midgets to touch it. Is this normal? (that the heat wont dispatch to the whole heatsink?). It's cold all over.

Cheers. And thanks! :)
8 answers Last reply
More about running full speed stress testing
  1. I'm not too familiar with the E8400 but the first thing I see is the multiplier. Normally with Intel Core 2 CPUs its 9, and drops to 6 under speedstep, so check your bios to see if it's set to 9 normally.

    Also, as far as what test you want to use depends on what you want to test. Typically errors show up in an hour or so but whenever I do an overclocking build I do 8-24+ hours (I ran my current build for 72 hours, overkill but I went away for the weekend unexpectedly)

    A CPU below 50 with a cold heatsink means that everything's working properly and that heat's getting the hell out quickly :)
  2. If you're running Vista, check your power management settings. Look at the processor settings, there will be a minimum and maximum setting (in %). If you are using a power saving plan the maximum will not be at 100% and therefore will not let the CPU run at full speed. If it is <100% change it and see if that solves your problem.
  3. Ah. Thank you both.

    It was the multiplier! It's at 9x now, i don't know why it was set at 8x.
    Also, i changed the power settings from balanced to High performance. . dunno if it changed anything but thank you for the notice.

  4. Are you running 2 instances of prime 95?

    I recommend you switch to Orthos, its far easier to use and gets the same results.

    get it here

  5. Well. . i'm in school now, and at home i'm running Prime95 at fourth hour.

    I was wondering, does it stress test both cores in the dual core processor? or only one?

    Anyhow, i choosed the setting blend in prime95 and i'm looking forward for the results. . I havn't seen the temp above 49. Even after i changed my CPU to 3ghz.
  6. 2 instances of prime95?

    Here's a multi-threaded version of prime95:
  7. I'm only running one "instance" i think (sorry does this mean, like, one program of prime95? English is not my native language :)).

    I just downloaded the newest version and ran the program in a blend test.

    by the way, your link is not working (or maybe it's mozilla?).
  8. uh well. . when i came back my computer had rebooted :S . . hmm
Ask a new question

Read More