My Palit GTX1070 "Jetstream"s downvolted to 975mV + overclocked to 2025 on core/ 4404 on memory (samsung) show 492~506 Sol/s on EWBF/dstm. Efficiency is about 3.25 Sols/Watt. Never use PL 'cause of unstable clocks and unnecessary high voltage. Downvolting works better for energy saving, stable voltage works better for hardware lifespan. Temperature is above 60 degrees in Celsium (mostly 52-56) while +19~+22 in room.
P.S.
Sorry for poor English (it’s not my native language))