So I have some new GL effects and I have to copy a framebuffer (1 color texture and 1 depth texture) to another framebuffer or textures to be used in a shader. After I ran it over with GPU Perf Studio I found out that a glBlitframebuffer takes about 10 times more than it does to call CopyResource twice on DX11. Heck, I even tried 2 x glCopyImageSubData which should do the exact same thing as CopyResource and it still takes 10 times more. What is going on there ?
PS: R9 280X, 14.6 drivers