We have problems doing a vmotion (ESX 4) from virtual machines from a Dell R710 to a Dell PowerEdge 2950. It gives a SSE4.2 error before we can vmotion it.

A quick solution is to set CPU Masks. To do this, do the following:

1. Shut down the server
2. Edit settings
3. Go to Options
4. Choose CPUID Mask
5. Select the Expose Options
6. Click Advanced
7. Set the following options:
   

   Feature	Level	Row	Mask
   SSE4.2	1	ecx	—- —- 0–0 —- —- —- —- —-
   	80000001	edx	—- 0— —- —- —- —- —- —-

8. Press OK twice

Now you can do a vmotion.