Virtual machine CPU...
 

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[Closed] Virtual machine CPU usage

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I'm running a Windows VM on my Windows laptop using VMware. Task manager is showing 15% cpu usage when both host and guest are idle. It's always done this. Why? I wouldn't care but it slashes my battery life in half nearly.


 
Posted : 31/01/2013 2:00 pm
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If you are sat in a chair, you are idle, but you are still burning energy.

It's just like that.


 
Posted : 31/01/2013 2:03 pm
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Jamie, you're useless

🙂


 
Posted : 31/01/2013 5:16 pm
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Hmm, seems promising, but I can't find anything in my settings about HAL.

You are much more useful than Jamie.


 
Posted : 31/01/2013 7:23 pm
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Have you changed the number of processor cores assigned to the guest OS after installation? That'd do it.

(Aside: I always knew that that this was an unsupported configuration, but never why. That link ^^ is the other half of the puzzle. Ta.)


 
Posted : 31/01/2013 7:53 pm
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Presumably VM Ware uses some processing power to keep the vm open?


 
Posted : 31/01/2013 7:54 pm
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<nods> Depends what you mean by 'idle' too, of course. "Idle" Windows systems are sometimes anything but, the OS could be doing $stuff in the background. Have you checked taskman on the guest?


 
Posted : 31/01/2013 7:57 pm
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Don't think I have changed them, no. I can't find the optoins mentioned in Woody's link at all. This is VMWare workstation 8.

The cpu on the guest is the usual 1-2%, on the host it's 15%. At least it was when I posted this, it's now down to about 5% but the fan is still going so it's clearly using power.


 
Posted : 31/01/2013 8:26 pm
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I get this quite often running W7 in parallels on my Mac - the VM is usually chomping away at about 15% when task manager within the guest says 1-2%.

Having scanned, scanned and scanned again for malware or viruses, I just put it down to general windows crapness. Probably windows update doing something in the background - it usually seems worse either just before or after windows decides it needs to update.


 
Posted : 31/01/2013 9:30 pm
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It's the ads on here.

😉


 
Posted : 01/02/2013 7:52 am
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I don't know about windows, but with Linux guests running older kernels on any virtualisation, it helps to reduce the clock wakeup frequency - normally from 1000Hz to 100Hz. Newer kernels are tickless so they're not continually interrupting the hypervisor & consequently have lower overhead.

[url= http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1005802 ]This[/url] WMWare link suggests windows experiences it too.


 
Posted : 01/02/2013 8:48 am