AMD phenom ii x6 showing up as single core

ndpw29

Prominent
Nov 10, 2017
2
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510
Hi,
I recently upgraded my CPU to a AMD Phenom ii x6 processor. I was experiencing very slow speeds so i checked task manager and it only shows one core, Device manager also only shows 1 core and so does CPU-Z, any help would be much appreciated.
Could this be a power issue as i only have a 400W power supply?
Thanks, Nick