We have the same OS, same application and same SQL Server running on 2 very simlar machines:
Windows Server 2003 R2 x64
MS SQL Server 2005 Standard x64
Dell PowerEdge 2900 (differ in number of processors)
On PE2900 with 2 dual-core processors (4 cores) SQL Server uses all 4 cores
On PE2900 with 4 dual-core processors (8 cores) SQL Server uses ONLY 2 CORES!
Can anyone tell why and how to make the latter use all 8 cores?