Can nvidia gtx 560 run efficiently with intel dual core e2220?

hi everyone!!
i'm having quite a dilemma on whether i need to upgrade my cpu(intel dual core e2220@2.4ghz) or my gpu(nvidia geforce 210@1gb ddr3 64bit)

my budget is limited to only 1 upgrade and its hard to see the next opportunity to upgrade again due to financial restriction.

so i've been looking around and i came to a conclusion that i can only afford to either upgrade my cpu to intel i5 3450@3.1ghz(bundled with gigabyte's h77 mobo n d3ram) or my gpu to nvidia gtx560(bundled with a new PSU).

i'm mainly playing games like dota2 and world of tanks but would love to play other system demanding games like mw3 or bf3 smoothly on my rig.

ps:
im currently running win vista 32bit if that would help. thx for ur help.