Old news and most likely cpu bottle necked. The gtx1080ti running on a similar system was only pulling 33900 so only a little faster. It answers little tbh as it's run at 720p and is old hat.
Well, i'm running a Haswell i5 at 4.5Ghz, i didn't see the GPU drop below 96% and that 96/97% was about the 1%, he was running a 6700K, that's a good chunk faster CPU.
I don't see that performance being CPU related.
And to be fair you're running an X58 920 @ 4.0Ghz? with respect i think even i can beat that.