Replaced a OEM Ge-Force 7500 LE with a Rad eon HD 4350, both cards have self destructed, clock of the 7500 was 550 mhz - 800 mhz with fan clearance of 5/8 inch .. 256 mb 512 shared. Power supply 400 watts . shaders 4.3 pix / 3 vertex. Please give best upgrade.