Hi, Could someone tell me, percentage wise, how better the Geforce 460Gtx is over the Geforce 260? Thanks!!It would vary from benchmark to benchmark. Just look at some. A 460 wouldn't be too much more than a 260 used anyways.Please note first that nVidia graphic cards aren't ORDERED by performance with the version numbers (they go down and up per series).

260GTX...
216 PROCESSING cores
Graphics CLOCK (MHz): 576 MHz
Processor Clock (MHz): 1242 MHz
Texture Fill Rate (billion/sec): 36.9
Supports DirectX 10

285GTX...
Two GTX260 glued together
Specs similar to that of the 275GTX

460GTX has...
336 Processing cores
Graphics Clock (MHz): 675 MHz
Processor Clock (MHz): 1350 MHz
Texture Fill Rate (billion/sec): 37.8
Supports DirectX 11

With the 460GTX there is a difference between the 768MB and 1GB version of about 5-10fps @ high resolutions. At both 1680 and 1920 resolution, the 1GB GTX 460 is roughly 10% faster than the 768MB card.

460GTX Memory (1GB GDDR5 vs 768MB GDDR5)
Memory Clock: 1800 (same)
Memory Interface Width: 256-bit vs 192-bit
Memory Bandwidth (GB/sec): 115.2 vs 86.4

260GTX Memory
Memory Clock (MHz): 999
Standard Memory Config: 896 MB
Memory Interface Width: 448-bit
Memory Bandwidth (GB/sec): 111.9

Bench mark will depend on your other computers specs and game,
but as a BASIC idea (using the same specs except card):

Crysis: Warhead - 1680x1050 - Gamer Quality
Nvidia 460GTX (1GB) - 41.1fps
Nvidia 260GTX (896MB) - 27.4fps

Crysis: Warhead - 1920x1200 - Gamer Quality
Nvidia 460GTX (1GB) - 33.8fps
Nvidia 260GTX (896MB) - 22.7fps

Crysis: Warhead - 2560x1600 - Gamer Quality
Nvidia 460GTX (1GB) - 19.2fps
Nvidia 260GTX (896MB) - can't handle

At high resolution, the fps difference is around 10fps increase with the 460GTX.
Lower resolutions improve up to 20fps with most GAMES.