The amount of misinformation astounds me.

While a better CPU may help manage your background tasks, it won't really help Minecraft once you reach a certain point. A faster processor is definitely something to consider.

For Minecraft, GPU speed is somewhat important, but sadly Minecraft is still stuck using outdated & deprecated OpenGL methods which use the fixed pipeline, and as a result a lot of the calculations are still done on the CPU. Mind you, this is all on one thread, so the speed of individual cores would be more important than the # of cores.

That being said, I do have an AMD 7870, and together with my six-core Phenom II it runs Minecraft rather nicely. Keep in mind that you should never be pushing for "more FPS" - you should be pushing for steady FPS. If you can manage to keep the FPS steady at your monitors' refresh rate (generally 59.85 or around that mark), then you're all good. There's no sense going past that, else you'll be seeing visual artifacts/tearing (not to mention our eyes wouldn't really notice any change past 60).

-P

For minecraft; no, probably not

For other games: yes. A very noticeable change.

minecraft does not gain any fps from a better gpu

if you want awesome fps get a quad core processor

also the amount of ram on your graphics card does not matter for minecraft
its used for textures and to improve loadingtimes