Graphic Card for Dual Monitor (light gaming)

[jiakuan]

Hi Guys

I currently have 2 monitors which are DELL U2410 and DELL 2209WA.
My graphic card is 5770, i usually play SC2 or LOL on U2410 under window mode, at the same time, i watch video or browse website with firefox on 2209WA, but the problem is sometimes FPS of game drop to 30, and a bit lag. So I am wondering should i get a new graphic card to enable me to multi-task ?

My cpu is i7 930
Ram: 6g


Thanks

 

[amuffin]

Gtx 560 or radeon 6870!