What are the differences between CUDA compute capabilities?

Question

What does compute capability 2.0 add over 1.3, 2.1 over 2.0, and 3.0 over 2.1?

Answer 1

The Compute Capabilities designate different architectures. In general, newer architectures run both CUDA programs and graphics faster than previous architectures. Note, though, that a high end card in a previous generation may be faster than a lower end card in the generation after.

From the CUDA C Programming Guide (v6.0):