GPUs still have higher memory bandwidth than CPUs though. So if you miss in caches all the time, GPUs can still potentially come out on top (as long as you can

GPUs still have higher memory bandwidth than CPUs though. So if you miss in caches all the time, GPUs can still potentially come out on top (as long as you can keep the higher memory latency under control, which the massive effective hyper-threading of GPUs should be able to help with). That's the point of using GPUs for solving memory-hard problems for mining those "ASIC-resistant" coins.