Hi Ivo,
That is interesting information.
One of the problems with comparing WEI between host and VMs (or even just between different VMs or virtualization platforms) is that the measurement is relatively opaque: We don't know the entirety of the information goes into computing the WEI or how it affects the outcome. More importantly, we don't know if virtualization overheads can be reflected accurately in the result, since Workstation does all sorts of interesting stuff to try to minimize the visibility of those overheads to the guest (i.e. by distorting the guest's perspective of time when the virtualization overhead is high)... so if the guest is timing particular operations, the numbers might not reflect any actual aspect of the VM's real-world performance! Hard drive performance can suffer due to host overhead and sparse-disk overhead, but it can be boosted by host OS disk caching far beyond the caching capabilities of the physical hard drive.
In summary: I would not put any significant weight in the WEI measurements. Instead, tune your VM's parameters to meet the real-world needs of the workload you are running inside it. Using the WEI to guide VM configuration will quite possibly give non-ideal results.
Cheers,
--
Darius