Not for the single-threaded integer-arithmetic case, AIUI - ADD is 1 IPC (at least when there are data dependencies) and pretty much always will be. In cases where branching happens, modern processes can maybe do more speculative execution, and obviously going from non-SIMD to SIMD is a huge improvement in the cases where a new processor lets you do that, so there are plenty of real-world improvements, but I don't think to the core case. I'm not an expert by any means though.