I recently got a Sony Vaio SZ2XP. When i first got it i'm sure i saw two processors showing in task manager, but since then i have done a re-install, and it is only showing 1.

I have turned off all power management, put it on "speed" mode, but it just won't seem to work in dual core mode. If i look in device manager, it shows the two processors (with no errors), and when i look in SiSoftware sandra that also shows as 2 cores. However when i run the benchmark included in Sandra, it comes out at roughly half the speed for the processor i have .(Core Duo T2500)

Has anyone got any ideas?