When I look in Activity Monitor in Mac OS X 10.8.3 on a Macbook Pro 15" Retina while running Chrome (Build 26.0.1410.64) in a Windows 8 Pro VM hosted in Parallels 8 (Build 8.0.18483) I see that the "Parallels VM" process is constantly showing 40-50% CPU usage, even when the VM is idle. At the same time the Win 8 Task Manager only shows 2-3% CPU usage for all running processes. Closing Chrome in the VM immediately drops the processor usage for "Parallels VM" on the Mac side down to 7-8% (Windows 8 Task Manager still shows only 2-3% CPU usage by all processes).
I can see this problem when Chrome is the only application running in the Win 8 VM.
This problem only happens when a web page is open in Chrome. Plug-in settings for Chrome are set to 'Click to play'. I am not clicking to play any plug-ins when I load a web page.
Some information about my setup:
My Parallels VM is set to use two CPU cores. This would explain why (when Chrome isn't running) I'm seeing about double the CPU usage for the "Parallels VM" Mac process as I see being used by all process when viewing Task Manager on the Win 8 side, since the Mac's activity monitor reports processor usage by all cores and combines those values for the display CPU usage value.
Parallels is running in full-screen (non-Coherence) mode.
Windows 8 Pro has all current updates installed.
Chrome 26 is a base install with default settings and no extensions are installed other than the default 'Google Docs' extension, which is disabled.
Does anyone else have this issue and, if so, have you found a fix?
Best Answer
I had a similar problem in Windows 7 guest OS under Parallels 8. This fixed it:
In Chrome, go to chrome://flags and set 'GPU compositing on all pages' to "Disabled". Restart Chrome
There is a bug report related to this with more details: http://code.google.com/p/chromium/issues/detail?id=172521