VMWare Player and Dual Core Processors

If you are using VMware Player with Windows XP as the host operating system running on a system with dual core processors you may have problems with sound timing and guest operating systems. The symptoms are frequent skips while playing audio under the guest operating system and periods when the audio seems to speed up and slow down. The issue appears to be a VMware Player bug involving virtual machine timing when VMware is run on a host hardware environment that has Dual Core processors.

A workaround for the problem is to set the CPU affinity of the process containing the VMware Player virtual machine instance. To test the workaround you can set the CPU affinity of the “vmware-vmx.exe” process in the Task Manager (right click on the line for the process and choose “Set Affinity…”). If you set the affinity to a single core while the guest operating system is playing audio you will hear the audio change speed for a few seconds then it will return to normal speeds. You will then notice that the audio sounds normal and the skipping has stopped. If this is the case on your system then the CPU affinity workaround will work for you.

Setting CPU affinity in Task Manager only affects the running process and it is not stored anywhere. The next time you run VMWare Player it will run with the default settings which is running on all cores. One way to make the CPU affinity setting change “stick” is to find the “imagecfg.exe” tool that shipped with the Windows 2000 Resource kit from Microsoft. You can either get it from Microsoft or find a copy elsewhere by doing a quick google check. The following is the command that I used for my single dual core processor system:

imagecfg.exe -a 0x2 "c:program filesvmwarevmware playervmplayer.exe"

At a glance it looks like the imagecfg tool modifies the actual executable so the change will most likely have to be repeated every time VMWare Player is updated.

Update: The recent VMware Player 1.0.2 release seems to have fixed all the dual core/SMP timing issues that I have experienced on my home system without the above workaround. I don’t currently run VMware Workstation at work on a dual core system so I’m not sure if the issue is still present in those releases.