(05-02-2014, 10:13 AM)feliks Wrote: Hello. I read that AVX2 version of GSDx has better performance in Software Graphics mode than SSE4.1, but I wonder: if I will be using Hardware Graphics mode with AVX2, it will has the same performance as SSE4.1 or worse?
My CPU is Intel i5-4670.
Greetings,
Feliks
Both are instruction sets extensions for the CPU, actually all those MMX, SSE and such are focused in float point processing and vectors.
Besides they don't replace the other, they are added.
Just as a simple example, once upon a time many graphical functions based on multiply two numbers and then add to one the original numbers (and are very common and often used) and so many programs did it till a new instruction was incorporated in the set that did it at once and then was much more effective. Former programs multiplying and then adding continued doing so, newer programs used a simple MAD instruction to do it. Later on it was further expanded as FMA (Fuzzed Multiply Add) instructions and so on...
Many such instructions exist on GPUs also, but in the case it is meant to the CPU and can be performed only in CPUs supporting the extension, of course.
Anyway, the rule is use the more advanced if you can, nothing from the formers are lost.
Edit: In the particular case the newer instructions helped the software mode due to making the CPU more efficient treating graphics (more specifically vectors) and then those instructions were in GPUs already or couldn't be used there.