vmware and Parallels high cpu when VM not working (100%)

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Level 1

15 points

vmware and Parallels high cpu when VM not working (100%)

Hi all,

I found that both Virtualization sw has the same problem and the same work-around, so the problem is inside MAC (sw or hw).

The simptom is high CPU and low performances even if VM machine does nothing - this happens with the same VM on both sw (Parallels 7 and VMware Fusion last rel.)

In both cases if I shut down the macbook and when restarting I reset NVRAM (alt-cmd-PR) the problem disappear.

Rebooting the macbook without shutting it down does not represent the problem; the problem rises again onl when shutting down and reboot from shutoff.

The high cpu problem is metioned both in Parallels and VMware support, but never togheter.

Anyone has seen the same issue or can replicate it?

At this point the problem is inside my MacBook probably but I don't know where to search for it.

MacBook Pro, OS X Mountain Lion (10.8.4), changed HD with SSD

Posted on Jun 21, 2013 3:04 AM

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Answer 1

Jun 21, 2013 3:32 AM in response to peterwhites

Which version of Windows are you running in the VM's?

I know Windows 7 & 8 will fire up various processes

if the system is idle for any length of time. They seem to

be all manner of cleanup/maintainance type tasks. At least in

my machines, these tasks will run for 5-10 minutes then things

return to an idle state.

Also, if you have the setting to compress disks enabled in Parallels

(not sure what it is called in Fusion), it will use the idle time to free up

unused virtual disk space and return it to the host system, in this case

a Mac.

Personally, I have never seen the situation where CPU usage way up

and stay that way.

Also, in the VM, is the screen saver enabled? The virtual video cards in

the VMs will suck up lots of CPU when the screen saver in the VM is active.

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Answer 2

peterwhites Author

Level 1

15 points

Jun 21, 2013 8:06 AM in response to woodmeister50

Hi,

this is a problem I have since I changed the HD to a SSD.

I thought it was a Parallels issue but now I'm quite sure there is something wrong in OSX. IN the mean time I moved from Lion to Mountain Lion, but nothing changed.

VM : XP 64b

No screen saver

no disk compress

The thing is that if I make a NVRAM reset when starting MacBook The issue does not affect VM's, otherwise every VM has the same issue (XP, Win 7, Linux - various dist).

After a NVRAM reset I can activate screen saver withou any problem; I noted also that when VM is consuming CPU it's also very slow and with poor performances.

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