My bad computer barely manage 2x boxing

1gb ram
amnd athlon 64 3.5
nvidiea gt 7600


crappy i know but now i'm considering this upgr package

AMD Athlon II X3 450 Triple Core, 3.2Ghz, AM3, 1,5MB, 95W, Boxed
Gigabyte GA-870A-UD3, 870, S-AM3 AMD 870+SB750, ATX, DDR3, USB3.0, SATA 6Gb/s, GbLAN, PCI-Ex(2.0)x16
Crucial DDR3 1333MHz 4GB KIT, CL9, Kit w/two matched DDR3 2GB, 240pin

and use my old graphic card, will this do big changes to how many i can box? i've heard that wow are more cpu demanding than gpu

any replies on this would be helpful