Graphic card recommendation

Cici Bebe

Honorable
Mar 14, 2013
1
0
10,510
I want to replace my current graphic card with a new one. I can spend 600$ maximum. But I don't want my system bottleneck my new graphic card. What would you recommend me?

i7 920 @ 3.8 GHz
Asus P6T SE
AMD Radeon 5870
Corsair 6 GB 1600MHz
High Power 1000W
Cooler Master 922

Many thanks