athlon 4200 x2 not being recognised properly?please help

Hi all,
I have recently upgraded to an Athlon 4200 X2 processor, from an Athlon 2600 Barton, but I'm not sure if it is performing properly. When I am playing games I have noticed a massive improvement however when installing new programs, rendering in Maya or general multi tasking in windows there doesnt appear to be any improvement. When i go to 'system' in the control panel it says its running at 2.2ghz but it also says 'model unknown'. Is this normal and am I just expecting too much from this processor? thanks