I think you might want to just invest in a new rig.
I run max on 1080p

Asus sabertooth 990fx
Amd 8350 fx 8 core @ 4.8 ghrz
Amd 7970 graphics card
4gigs of DDR3 ram @1900mhrz

Idk what my frame rates are but I usually stream 1080 on twitch.tv,
All I can say is in fate battles with around 50 people spamming stuff the game still runs pretty smooth