I am trying to benchmark Cycles performance without SSE, with SSE only, and with AVX instructions. I am finding weird behavior where if I switch off the "WITH_CPU_SSE" flag in CMakeLists.txt, the program does not render the full image. I tried this using the demo file for the Cosmos Laundromat Demo. With SSE off, it only renders a small portion of the sky. Not sure why this is happening?
Further, what is the easiest way to build blender/cycles without SSE, with SSE only, and with AVX instructions? Has anyone done performance benchmarking to see what performance impact these make?