Does anybody know if using very small local sizes in compute shaders will hurt performance?
eg. If I do this in a shader:
layout (local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
Will it be slower than if I use larger sizes (eg. x=8, y=8)?
If size 1 is bad for performance then what's the recommended size? Is it a rectangle based on the value returned by aglGetIntegeri_v(GL_MAX_COMPUTE_WORK_GROUP_SIZE...)?
I've read many, many web pages today and the whole issue of "threading" in OpenGL compute shaders is about as clear as mud.