FYI, this setting increased the performance of my guest box a lot. My host is a 64 bit Linux box with BFS and the timer is at 1500hz. If you can enjoy virtualization like I do I would like to recommend to check this out. My box has 6GB physical ram and I created a 5GB ramdisk but it should also work with only 2GB of physical ram. tmpfs seems to dynamically allocate wanted ram. host.cpukHz needs to be exactly the host box cpu speed. mem.ShareScanThreshold needs to be exactly the guest box ram size. Start the guest box and install the vmware tools and let it install the virtual drivers for the hardisk, video card and so on. I've created a guest box with Windows XP SP3 OS and it works like a charm. It could be a little faster but my box is cpu limited. It's only a 2.2Ghz 64 bit dual core cpu and it's doesn't support hyperthreading. It's also good if the guest box has enough ram (2GB).
# create a ramdisk
tmpfs /dev/shm tmpfs defaults,size=5G,nr_inodes=5k,mode=700 0 0
host.cpukHz = "2400000"
host.noTSC = "TRUE"
ptsc.noTSC = "TRUE"
# I/O fix
prefvmx.useRecommendedLockedMemSize = "TRUE"
prefvmx.minVmMemPct = "100"
# temp file fix
mainMem.useNamedFile = "FALSE"
MemAllowAutoScaleDown = "FALSE"
# Cpu fix
# Disable page sharing
sched.mem.pshare.enable = "FALSE"
# Disable 3d
mks.enable3d = "true"
roamingVM.enabled = "FALSE"
roamingVM.useBackgroundSync = "FALSE"
# Disable logging
logging = "FALSE"
# Disable unity
isolation.tools.unity.disable = "TRUE"
unity.allowCompositingInGuest = "FALSE"
unity.enableLaunchMenu = "FALSE"
unity.showBadges = "FALSE"
unity.showBorders = "FALSE"
unity.wasCapable = "TRUE"
# Disable snapshot
snapshot.disabled = "TRUE"
mainMem.partialLazySave = "FALSE"
mainMem.partialLazyRestore = "FALSE"
priority.grabbed = "high"
priority.ungrabbed = "normal"
Here is some explanation: http://vmfaq.com/entry/25/. It's also good to compile a kernel with max 1khz timer freqquency.