Cheaper to upgrade or buy new??

[mattr 76]

I have an old Quicksilver G4, and have thought about upgrading the CPU to a G5 or maybe even dual G5, is it worth it, will I see much of a change or would it be cheaper and faster to buy a new mac mini?? or Imac??

 

[Genghis Khan]

go for at least a mac mini...intel chips have rendered IBM processors useless