Hello,
I do have a server with this processor:
http://processorfinder.intel.com/details.aspx?sSpec=SL8Q5
It does support enhanced speedstep but I it's not available in ESX4i ?
Also the processor is detected as a socket 478 instead, but it's a socket 775 processor.
ESX4i runs fine, 32bit OS'es ofcourse but no error's