TechSpot

Windows 8 bug on overclocked PCs found to alter benchmarks

By Scorpus
Aug 20, 2013
Post New Reply
  1. A bug relating to the real-time clock has been discovered in Windows 8, which causes inaccurate benchmark results on over- or under-clocked systems. When a system's CPU clock frequency is adjusted from within the operating system, the software time-keeper no...

    Read more
     
  2. misor

    misor TS Maniac Posts: 1,020   +153

    Is it really a windows 8 bug or the benchmarks themselves have bugs for not being able to cope up with changes due to 'underclock' and 'overclock'?
    (bear with me; I'm not good at math and I barely understand those benchmarks)
     
  3. Chazz

    Chazz TS Enthusiast Posts: 634   +60

    I don't know details about this, but from what I gathered from this article its a windows issue. The clock fails to track time properly. Its being sped up(under clocked) or slowed down(overclocked). Id assume these benchmarks test performance over time, or track time taken to complete a task and rely on the system clock for this data. A lot of things depend on accurate time telling . I have windows 8 with a overclocked CPU, I did this from the bios though so I don't get this bug. So ya, seems to be an OS thing.
     
    misor, cliffordcooley and Darth Shiv like this.
  4. Not likely, since this would affect any timed benchmarks which used systemtime() to allot time to complete a task. In this case more time to complete a sequence of tasks would artificially boost scores for Win 8. Similar to if I asked 8 people to run as far as they can within ten minutes, but one of the runners is actually given 11 minutes to run instead. Assuming the person given extra time will actually use it to run further, he/she would seem to be able to run faster, since speed = distance/time. So the person with the highest distance run would be considered fastest; however the unequal timing would skew results in favor of the person given more time. Thus this method of measuring speed is flawed if time between systems cannot be accurately accounted for. Therefore this could potentially affect all such timed benchmarks in some way.
     
  5. JC713

    JC713 TS Evangelist Posts: 7,018   +912

    This is a big hit for Win8.
     
  6. amstech

    amstech TechSpot Enthusiast Posts: 878   +230

    Anyone who uses software to overclock thier PC is a poser anyways :p .
     
    misor, JC713, St1ckM4n and 2 others like this.
  7. Chazz

    Chazz TS Enthusiast Posts: 634   +60

    I'm not quite sure what windows version you've used where you feel comfortable overclocking via windows, but you'd get more options via your bios. The last thing you'd want is less options if you like to overclock. I hope you don't flash bios via windows too.
     
  8. Darth Shiv

    Darth Shiv TS Evangelist Posts: 1,169   +176

    I don't think they mean it is a bios vs OS overclock. They mean if the OS uses a software based clock for reporting system time. Most machines have hardware clocks but you can override the system time source to use a software clock. The software clock in Win8 is buggy.

    E.g. if I have a hardware clock, I ask it "how much time has elapsed?". It tells me, accurately, what the time is.

    If I have a software clock, I can't ask it what the time is because it doesn't track time. It tracks processor ticks. So to get the time, you need to know what the time was before, how many ticks have elapsed, what clock speed those ticks were at then you can work out the new time. If one of those numbers is inaccurate, your time calc is off.
     
    misor and Chazz like this.
  9. St1ckM4n

    St1ckM4n TS Evangelist Posts: 3,473   +622

    No, I flash my BIOS via the BIOS.
     
    Chazz likes this.
  10. Darth Shiv

    Darth Shiv TS Evangelist Posts: 1,169   +176

    Both methods I think prove that it doesn't matter where you flash your bios. Once it is "loaded", sounds like you can do anything to the bios firmware from any environment.

    E.g. if you flash your bios in windows and it "fails" then don't restart your computer. Try flash it again (check your bios file isn't corrupt, redownload if necessary etc), cause while you haven't restarted, you can try to repair the firmware before it is needed (which is when your computer boots of course).
     
    misor likes this.
  11. Samsung showing MS some benchmark tricks?
     
    St1ckM4n likes this.
     
  12. JC713

    JC713 TS Evangelist Posts: 7,018   +912

    Right, this is only with desktop OCing. I forgot about that.
     
  13. misor

    misor TS Maniac Posts: 1,020   +153

    haha! I flashed my intel dh55tc mobo (with intel i3-530) in the windows milieu.
    (though I also made a bootable cd flash in case something happens)
     
    Chazz likes this.
  14. cliffordcooley

    cliffordcooley TechSpot Paladin Posts: 6,090   +1,519

    Thats just it, if something happens your system will be bricked and the CD will do no good. Thats why they started placing BIOS backup solutions on motherboards with the push of a button.
     
    misor likes this.
  15. Wagan8r

    Wagan8r TS Guru Posts: 593   +47

    What's missing from this story is that if you overclock your PC from the BIOS, the benchmark results are completely accurate. Only by adjusting the clockspeed within the OS produces the skewed results.
     
  16. misor

    misor TS Maniac Posts: 1,020   +153

    how did you know that?

    thanks for the caution, I thought bios flashing by any means provided by the mobo vendor are equally safe (relatively).
     


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...
Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.