Marc Charbonneau

Since I’ve been using VMware Fusion a lot recently, I’ve started looking around for performance tips (both to get the best results from inside Fusion, and avoid slowing my MacBook Pro to a crawl when it’s running in the background). Besides buying more RAM or a faster Mac, here are a few things you can do when setting up a new VM that may not be immediately obvious:

• Install the 64bit version of your guest operating system. See this post by a VMware software engineer for the technical reasons why. The big drawback to running 64bit Windows is lack of driver support, and since drivers are provided by VMware, it's not a huge concern in the VM world as it is with physical hardware.
• Use SCSI rather than IDE hard disks; the VMware SCSI driver is faster. Since the Windows XP installer doesn't won't recognize SCSI disks without an additional driver, you might want to use Fusion's "easy install" option.
• Don't use more than one CPU per guest. Emulating two CPUs will lead to horrible performance in my experience.
• Use fast, external hard disks if possible. The goal is to reduce contention between the host operating system or other VMs, especially if you're on a notebook with a slower 5400rpm hard drive.

Thanks to Tony Arnold and various online forums for this information.