Top GeForce video cards have 480 GUDA cores (60 multicores by 8 stream each). They are like general purpose CPUs, but with specialized instructions, registers and memory working modes, and are oriented to float-point processing.
Top Radeon video cards usually have less speed than GeForce cards (at two times less price!). However, the official specs state that they have 1408 stream processors and 22-24 SIMD engines (by 16 streams each).
What are stream processors, and what does SIMD engine mean? Is a SIMD engine like CUDA cores? Are stream processors exactly the same as ALUs?