CPU or GPU is more important?

[IbnSolmyr]

I believe GPU is effectively, at this stage of developpement, the most important, because : my new rig is good but i kept my previous GC and i experiance a lot of stutters, and fps is rather poor...
Gigabyte X58 UD3R, i 7 950 OC @ 3,22 Ghz, 12 Go @ 1600 Mhz, SSD OCZ Vertex 2 120 Go, and "only" Sapphire HD 4870 2 Go OC @ 780 Mhz core and 1090 Mhz vRAM.