GeForce GTX 460 768MB

The GeForce GTX 460 1 GB comes with seven SMs enabled out of eight, which cuts the number of available CUDA cores to 336 and texture units to 56. The Nvidia GeForce GTX 460 768 MB uses the same configuration of 336 CUDA cores and 56 TMUs.

But move past the front of the pipeline and the two cards start to differ. The 1GB version uses all four ROP partitions, delivering up to 32 pixels per clock and benefiting from a full 256-bit memory bus and a full 512KB of L2 cache. Meanwhile, the 768MB card uses three of the four partitions, with the ROP count reduced to 24, the memory bus reduced to 192 bits, and the L2 cache reduced to 384KB.

Nvidia hasn't made any other changes to differentiate these cards, though, which is good news. Clock speeds are identical, with the fixed-function units running at 675 MHz, the shader processors at 1350 MHz, and the GDDR5 memory running at a physical frequency of 900 MHz (which gives an effective frequency of 3600 MT/s).

 The GeForce GTX 460 768 MB, priced in line with the Radeon HD 5830, is slightly less attractive. Smaller memory hurts performance at high screen sizes when anti-aliasing is active, and narrowing the memory bus width resulted in reduced bandwidth, which slowed down performance.