Thanks lenzker, thats correct. Nehalem genartion processors are not supported in Sandy-bridge. the formula you explained is the right one, i've misinterpreted the explanation in KB.
We can do two things to confirm the EVC mode.
1. Use the VMware compatibility guide web app. It will tell the supported EVC mode. In this select the option "Search by EVC mode" and give the processor as keyword.
2. User VMware CPU identification utility.