40 MH/s on overclocked settings. Probably 45-50 Mh/s with BIOS mods and driver optimizations?
31-33MH/s should be already overlocked, so by no mean Rega could reach 50mh/s in the near future...
And the vega cards would cost twice watts per mh/s than gtx 1070... shitty card, either from gaming or mining...