Due to failure of cooling fan over the graphics card and unable to get the replacement fan (DC BRUSHLESS FD7015H12S - DC 12V, 0.43 AMP), I want to replace the existing Radeon HD 5770 - 512 MB with 1GB. Using CPU= QUAD CORE, Mother Board = ABIT IP35 PRO, Memory = 3 x 2GB (6GB) DDR2, 800MHz, PCIe 16x and Monitor = BENQ EW2740, Cooler Master: RS-460-PCAR-A3 with max. power of 401.5W. Please suggest a better Graphics Card. Thank you.