Hi,
I am using VirtualBox 3.0.10 on an Intel core2duo T9400 at 2.53GHz.
Host OS: Windows Vista
Guest OS: Fedora Core 10 (Linux version 2.6.27.38-170.2.113.fc10.i686)
Everything is fine.
But I am getting a weird detected frequency anytime I reboot the Guest OS...
Here is a sample of detected frequencies:
kernel: Detected 273.212 MHz processor.
kernel: Detected 1630.253 MHz processor.
kernel: Detected 212.622 MHz processor.
kernel: Detected 105.430 MHz processor.
kernel: Detected 2425.616 MHz processor.
kernel: Detected 99.620 MHz processor.
Why is the detected frequency changing?
How can I get the maximum frequency at every reboot?
Thanks for your help!
V.
[solved] detected frequency
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[solved] detected frequency
Last edited by vthnts on 9. Dec 2009, 16:02, edited 1 time in total.
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Re: detected frequency
Is this on a laptop?
This would be set in the operating system, not in VirtualBox.
This would be set in the operating system, not in VirtualBox.
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Re: detected frequency
Time keeping inside a guest sometimes has problems, and such problems could affect calculations such as the CPU clock you give.
See: http://www.virtualbox.org/ticket/3135
Do you have any: 'TM: Giving up catch-up attempt...' lines in your VBox.log?
See: http://www.virtualbox.org/ticket/3135
Do you have any: 'TM: Giving up catch-up attempt...' lines in your VBox.log?
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Re: detected frequency
Yup, this is on a laptop.Is this on a laptop?
This would be set in the operating system, not in VirtualBox.
Nope.Do you have any: 'TM: Giving up catch-up attempt...' lines in your VBox.log?
But, um... interesting..., here is what I found in the two latest VBox logs while looking for "TM":
00:00:02.714 TM: cTSCTicksPerSecond=0x104ad0c0 (273 338 560) fTSCVirtualized=true fTSCUseRealTSC=false
00:00:01.151 TM: cTSCTicksPerSecond=0x612c7940 (1 630 304 576) fTSCVirtualized=true fTSCUseRealTSC=false
Matching the Fedora boot messages:
kernel: Detected 273.212 MHz processor.
kernel: Detected 1630.253 MHz processor.
Is there a way to fix this or is it a VirtualBox bug?
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Re: detected frequency
AMD or Intel CPU, family, model, and what does the fMaybeUseOffsettedHostTSC value say (on the line below)?
Try:
Then turn off the VirtualBox service / time-sync daemon in the guest (I'm not sure how to do that for a Linux VM) and see how the VM time tracks and also if any 'TM: Giving up catch-up attempt...' lines then appear in your VBox.log.
Maybe set 2/3 of that amount, = 1686666667 (based on a crazy theory...)
I'd say it's a VirtualBox bug. I'd say it's VirtualBox doing the best it can to handle a CPU that has a varying TSC clock?
Try:
Code: Select all
VBoxManage setextradata "<VMName>" "VBoxInternal/TM/TSCTicksPerSecond" 2530000000
Maybe set 2/3 of that amount, = 1686666667 (based on a crazy theory...)
Last edited by MarkCranness on 10. Dec 2009, 00:28, edited 2 times in total.
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Re: detected frequency
It used to be fMaybeUseOffsettedHostTSC=true in previous boots.
After executing the code you provided:
00:00:00.799 TM: cTSCTicksPerSecond=0x96ccbc80 (2 530 000 000) fTSCVirtualized=true fTSCUseRealTSC=false
00:00:00.799 TM: fMaybeUseOffsettedHostTSC=false TSCTiedToExecution=false TSCNotTiedToHalt=false
And Fedora now sees the right frequency:
kernel: Detected 2529.899 MHz processor.
A good enough workaround for me.
Thanks a lot!
After executing the code you provided:
00:00:00.799 TM: cTSCTicksPerSecond=0x96ccbc80 (2 530 000 000) fTSCVirtualized=true fTSCUseRealTSC=false
00:00:00.799 TM: fMaybeUseOffsettedHostTSC=false TSCTiedToExecution=false TSCNotTiedToHalt=false
And Fedora now sees the right frequency:
kernel: Detected 2529.899 MHz processor.
A good enough workaround for me.
Thanks a lot!
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Re: [solved] detected frequency
(fMaybeUseOffsettedHostTSC was set true when VirtualBox had identified your CPU as having the 'Invariant TSC' feature.)
You might want to check that your VM is keeping time accurately.
You might want to check that your VM is keeping time accurately.