Used allanmac's code (https://gist.github.com/allanmac/f91b67c112bcba98649d) from devtalk.nvidia.com to test TLB thrashing and compiled it with nvcc -m32. It didn't alleviate the TLB thrashing issue; 970 still dives like a stone past 2GB. Not sure if this is representative of memory bandwidth in Ethash though, just sharing to see if anyone can tweak and improve the TLB situation.