Overclockability of CPUs / GPUs

[SSA]

On a purely hypothetical basis, what's the potential for overclocking:

a) Athlon 64 CPUs

b) nVidia 7600GT GPUs

On the same note, what's a good aftermarket HSF for the above?

Cheers.

[-ChEM-]

a:
singles:
low end venice = good
low end venus core = good (opteron)
dualies:
manchester 3800+ = good
low end denmark = good (opteron)

others not too good, you can get 200-300mhz

b:
gpu clocking never gets amazing figures apart from maybe the x800gto2 which regularly hits a 40% boost but thats due to pipeline unlocking (100% success rate) as well as the fact that theyre good OCers

you should get 10% out of any card

[SSA]

Cheers, v. helpful info