使用AVX intrinsic而不是SSE不能提高速度——为什么?

I've been using Intel's SSE intrinsics for quite some time with good performance gains. Hence, I expected the AVX intrinsics to further speed-up my programs. This, unfortunately, was not the case until now. Probably I am doing a stupid mistake, so I would be very grateful if somebody could help me out.I've been using Intel's SSE intrinsics for quit