I think I hit my GPU's limit. With voltage and fan speed maxed (+87mv, fan was 100%, giving me 59-60°C), open air, I managed to bench my 970 at 1356MHz core (+305, boosts to around ~1545mhz avg in valley, max is ~1590mhz) and 7.92GHz memory (+420 or so). Even that was not super stable, I'd say...