After a lot of investigation and re-testing, the solution to this seems to have been found.
- Disabled Intel Speedstep in the BIOS.
- Added the following to /etc/vmware/config (after this, performance was much improved, but not perfect)
prefvmx.useRecommendedLockedMemSize = "true"
prefvmx.minVmMemPct = "100"
MemTrimRate=0
sched.mem.pshare.enable = "FALSE"
mainMem.useNamedFile = "FALSE"
3. Disabled khugepaged
echo never > /sys/kernel/mm/redhat_transparent_hugepage/enabled
Hopefully this will help someone else who may get a similar problem.