Viewing 40 posts - 1 through 40 (of 46 total)
  • Why is my CPU not going flat out?
  • molgrips
    Free Member

    Quad core i7, and I’m running a cpu intensive task, but the speed says it’s at 36% in resource manager. Wtf?

    Max speed set to 100% in power options
    Cooling policy set to active
    Machine still stone cold underneath so no fan on
    Disk I/O low

    scu98rkr
    Free Member

    The process can only use one core ?

    Its not a multicore application ?

    Ie the CPU intensive task is using 25%.

    The other 12% is used up by other processes or runnings the OS ?

    Stoner
    Free Member

    if you RHC on the task, have a go at changing the priority of the task

    allthepies
    Free Member

    Does task manager (performance tab) show one CPU core maxed out ?

    molgrips
    Free Member

    4 cores being used.

    CPU is only at 23% or so total usage, because only half the cores are being used and it’s hyperthreading waffle, but the cpu SPEED is showing as 36%, not utilisation.

    Why has it not upped itself to 100% when it’s got work to do?

    Drac
    Full Member

    Because it doesn’t need to for the task in hand?

    Cougar
    Full Member

    Plug the power lead in properly?

    molgrips
    Free Member

    Why would it think that I don’t need it done asap?

    Good call Cougar but it IS plugged in, already checked. Battery cooling policy is passive, but it’s definitely on A/C power.

    It’s a Java app that I’ve kicked off myself, the process itself is set to normal priority.

    Drac
    Full Member

    Did you send it a memo?

    scu98rkr
    Free Member

    its got to be its only using 1 core. What software is it ?

    mboy
    Free Member

    Software won’t be written to take best advantage of the CPU.

    In fact, there’s not much software written that will max out a hyperthreaded quad core i7 processor. Though Handbrake will if you want to do some video ripping, and have a desire to see your CPU maxed out!

    almightydutch
    Free Member

    Have you got enough memory to support the CPU at flat out speeds?

    What makes you think its a CPU intensive task?

    Try turning OFF the turbo function, great for power saving but not always great for real world applications

    scu98rkr
    Free Member

    Surely the only other thing it could be is the application is very I/O intensive as well as CPU intensive.

    And your CPU power outweighs your I/O throughput. Ie the CPU is not getting enough info to work at 100%.

    Is you harddrive constantly going ? Do you have little memory.

    But more like to be the application is not parallelised.

    almightydutch
    Free Member

    Run IntelBurnTest for a couple mins to amke sure everything is working as it should

    WARNING: Make sure your cooling is more than adequate and dont blame me when it goes pop!!!

    GrahamS
    Full Member

    4 cores being used.

    Are you just looking at overall CPU usage or a separate usage for each core?

    I’d suggest that either the process isn’t written to use four cores, or is badly written and doesn’t do it very efficiently, or it is constrained by some other aspect (memory, disk speed, network speed etc)

    molgrips
    Free Member

    It’s a Java app server, it’s got 274 Windows threads, and Windows has distributed them across 4 cores as it does.

    And, the question is not about CPU usage, it’s about CPU max frequency.

    GrahamS
    Full Member

    It’s a Java app server, it’s got 274 Windows threads, and Windows has distributed them across 4 cores as it does.

    Doesn’t help. 273 of those threads could be sitting blocked waiting for the 274th to do something interesting (or waiting on disk, memory etc)

    And, the question is not about CPU usage, it’s about CPU max frequency.

    Related though innit? No point it stepping up the CPU speed if there is no work to do.

    almightydutch
    Free Member

    Might well be about usage Mol, but if the usage isnt enough to warrant boosting up the speed then why would it.

    jambalaya
    Free Member

    The programme has not been written to efficiently use multi-processing as per @mboy’s/@GrahamS comments.

    Plus suggestions above, the task could be doing a lot of IO as it’s using memory inefficiently so the processors are “waiting for data”

    FWIW I was writing code to try and use multi-processors back in the 1970’s and 80’s – it was very hard to do and only certain very specific scientific type applications were able to being to use the processing power efficiently. Did my masters around parallel processing. Ah those were the days, super computers you could sit in surrounded by cooling units. Nostalgia’s not what it used to be eh ?

    molgrips
    Free Member

    Intel burn test – like it, ran it, maxed all 8 virtual cores which no other app has ever done – but cpu frequency still at 36%.. grr..

    almightydutch
    Free Member

    IF IBT isnt maxing out the PCU then you have some settings wrong in the BIOS somewhere.

    Something to do with Turbo freq step up. No way in hell would IBT not max out the CPU.

    Check BIOS/power settings(not windows based ‘profiles’) and CPU clocking in BIOS too.

    What Motherboard is it?

    GrahamS
    Full Member

    but cpu frequency still at 36%

    Where are you seeing this frequency reported? Do you know it is accurate?

    almightydutch
    Free Member

    Are you sure its 36% and not 3.6 Ghz its reporting?

    Stoner
    Free Member
    molgrips
    Free Member

    Might well be about usage Mol, but if the usage isnt enough to warrant boosting up the speed then why would it.

    Doesn’t matter. If it’s only using one core then that’s all the more reason to up the CPU clock to 100% isn’t it?

    FWIW I was writing code to try and use multi-processors back in the 1970’s and 80’s – it was very hard to do and only certain very specific scientific type applications were able to being to use the processing power efficiently

    If I were running one single thread (which I’m not) then it should be running on one cpu only, right? And that cpu ought to be running at 100%, oughtn’t it, since it’s busy?

    float
    Free Member

    you havent changed any BIOS settings have you?

    molgrips
    Free Member


    rm by molgrips, on Flickr

    Rio
    Full Member

    What’s the maximum processor state set to in the advanced settings under power options? Needs to be at 100% to max the cores.

    molgrips
    Free Member

    Using Intel Burn Test, all cores at 100%, freqency still at 36%


    rm2 by molgrips, on Flickr

    As above, in power options it’s set to 100%.

    GrahamS
    Full Member

    If I were running one single thread (which I’m not) then it should be running on one cpu only, right? And that cpu ought to be running at 100%, oughtn’t it, since it’s busy?

    Yes, though only if it was an entirely CPU-bound task and not waiting on anything else.

    (which the Intel Burn Test should be)

    retro83
    Free Member

    Download and run CPU-Z and check what it says. Possible the resource monitor is not reporting correctly.

    Also a cursory google reveals someone with a similar issue:
    http://www.tomshardware.co.uk/forum/298884-10-frequency-problem-2600k

    Cougar
    Full Member

    Ah!

    Laptop, yes? Has it hibernated recently? Try proper shutdown and restart.

    Anything in Event Viewer that might give you a clue?

    When you say it’s stone cold, is that the CPU side of the board or the heat sink side? (Where I’m going with this is, if the heat sink isn’t making a proper connection with the CPU, the HSF will be cold but the CPU will be overheating.)

    Rio
    Full Member

    the HSF will be cold but the CPU will be overheating

    Running coretemp or similar would tell you this, or just leave it to cool for a bit and see if that improves things, although if you’ve been running Intel burn with a dodgy heatsink that may take a while!

    GrahamS
    Full Member

    if the heat sink isn’t making a proper connection with the CPU, the HSF will be cold but the CPU will be overheating

    Oooh interesting theory. But wouldn’t the fans be going mental?
    (or the BIOS beeping away)

    Whack SpeedFan on there and see what it reports?

    mst
    Free Member

    Try less threads ?

    4 per core ?

    Probably spending too much time context switching (my experience is unix based, not to sure how Windows manages that kind of thing)

    molgrips
    Free Member

    It’s now slightly warm in the middle, and by the van vent. Not hot though.

    Just restarted – BIOS checks out, all the Speed Step options were as they should be.

    CPU temps hovering around 48C no matter what I do. CPU-Z tallies with resource monitor too. Interestingly, I also appear to be using integrated graphics rather than the Quadro that’s installed.. hmm…

    IA
    Full Member

    Possibly related, an i7 won’t turbo to its max freq. with multithreaaded loads, only single threaded.

    What freq does CPUz say it’s running at, what’s the exact CPU model?

    philconsequence
    Free Member

    overclock your pentium 56, that’ll do it x

    coffeeking
    Free Member

    And, the question is not about CPU usage, it’s about CPU max frequency.

    Why would it bump the frequency if it’s not running at 100% utilisation?

    molgrips
    Free Member

    Fixed.. I googled my exact laptop model (Lenovo W520) and it’s a really common issue, fixed by a BIOS update.

    Boring answer.. sorry 🙂

    Thanks for helping.

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