How to measure GPU GFLOPS on a non-unified shader system?

Question

my question is because there are some old GPUs that does have vertex shaders and pixel shaders, I don't know how I can measure GFLOPS with that kind of GPU. I know you can measure GFLOPS using Core Speed x ALUs x 2 (I don't know what this "2" is, if someone can answer that too it would be great!). But for a GPU that doesn't have unified shaders how can I measure it? Thanks in advance.

Answer 1

I think that it can be measured independently. I mean, you should measure vertex shader performance without pixel shader work (for example, draw backface culled triangles), then measure pixel shader performance without (significant) vertex shader work (like full screen triangles). Then add the two numbers together.