NVIDIA vs AMD: GPGPU performance

Question

I\'d like to hear from people with experience of coding for both. Myself, I only have experience with NVIDIA.

NVIDIA CUDA seems to be a lot more popular than the competi

Answer 1

The main difference between AMD's and NVIDIA's architectures is that AMD is optimized for problems where the behavior of the algorithm can be determined at compile-time while NVIDIA is optimized for problems where the behavior of the algorithm can only be determined at run-time.

AMD has a relatively simple architecture that allows them to spend more transistors on ALU's. As long as the problem can be fully defined at compile-time and be successfully mapped to the architecture in a somewhat static or linear way, there is a good chance that AMD will be able to run the algorithm faster than NVIDIA.

On the other hand, NVIDIA's compiler is doing less analysis at compile time. Instead, NVIDIA has a more advanced architecture where they have spent more transistors on logic that is able to handle dynamic behavior of the algorithm that only emerges at run-time.

I believe the fact that most supercomputers that use GPUs go with NVIDIA is that the type of problem that scientists are interested in running calculations on, in general map better to NVIDIA's architecture than AMD's.