I am using ESXi 3.5 U5 on 2 socket cpus with HT which gives 4 logical cores. My VM is running Windows 2003 Server with 2 vCPU each. On one physical server I have two vm running and on another physical server only one vm. What I noticed is by default the logical cores 1 and 3 on both physical servers is grossly underutilized compared to logical cores 2 and 4. Ratio of over 2:1. Is there setting to allow for all logical cores to be used? Should I increase the vCPU on the vm from 2 to 4? One is a domain controller, one is multipurpose WSUS, antivirus server (using SQL and MYSQL) and the third is a web server with a SQL server as well.