Macman said:
I know it can be done, just not sure how exactly, though you'd need to remove a few jumper pins some soldering is involved.
This was true for G4s, which used a very slow FSB (compared to it's core frequency) and simply multiplied it to achieve higher clockspeeds (just like Intel/AMD does).
For example, the 1GHz, 1.25GHz and 1.42GHz in the MDD all had the same FSB, just different multpliers through soldered jumper settings (and different CPUs actually), while the G5 in PowerMacs (except the recent single 1.8GHz) all run at double FSB, this means the speed increase was achieved by setting the FSB higher. Playing with this is a lot more delicate, as changing the FSB will raise the probability of an unstable system, as all system parts, PCI and AGP cards included, will get higher frequencies, which they surely won't work with.
Overclocking is nothing less then playing with the constructor's tolerances. Doing so with one component (the CPU or the video chip) can be succesfull, though it won't significantly increase overall system performance.
But if you overclock the FSB, you overclock everything, the problem is that every single chip or additional card might have very different tolerances, so making everything working together is quite difficult.
And as far as I know no G5 has yet been overclocked, and, honestly, I don't think it will happen soon...it's much more complicated than it was for the G3 and G4.
