Does your Farm support the new Fault Tolerance feature in vSphere?
Today, I am researching ways to figure out if VMware Farms are going to be FT capable. RUN-VIRTUAL has a great Host-CPU feature utility that you can point against your VC to list out compatibilities.
There is also an official VMware Site Survey Tool that will produce a report detailing any issues that may exist in your farm related to the new Fault Tolerance features.
Of course, for a more static view of the CPU’s supported, there is always the official VMware KB Article :