Dual core upgrade

I have an AMD X2 4000+ @ 2.1 GHz, Is it worth it to upgrade to a 5600+ @ 2.8 GHz

I don't think I can overclock. Would I see a noticable performance increase?

I have an AMD X2 4000+ @ 2.1 GHz, Is it worth it to upgrade to a 5600+ @ 2.8 GHz

I don't think I can overclock. Would I see a noticable performance increase?

Vstreep

Wait until the Phenoms come out to make any changes so you can see all your different options. Going to a 5600+ from 4000+ is a pretty good upgrade, but it would be good to see in any case.

As for performance increases, you probably wouldn't NOTICE any unless you are decompressing large file archives and encoding video on a regular basis, but it would show a performance increase all around.