We have just migrated a database to a new server that has two dual-core CPUs. We are noticing that Oracle seems to max out at 25% of the total CPU power on the machine, even when it is running highly compute intensive processes that would max out the CPUs on our prior machine. The new server is Windows 2008 64-bit and the old server was Windows 2003 64-bit. Is there any setting in Oracle or the Operating System that would be limiting the CPU usage for Oracle? It does run on all four CPUs (CPU affinity) but the total usage does not exceed 25%.