I've been meaning to do some extensive testing in the power-efficiency arena. Rough calculation, it seems I am costing myself $0.25 per day on one rig by using this PSU. But at this point, 750B might be an overkill for me. I'm wondering if crappy riser cables also play a factor...
Not likely the riser cables, just efficiency of the power supply likely. My other machine is on a Supernova 650 Gold - I bought nice re-usable components for the things that have a life after crypto mining...
Again, we can't predict exactly where the difficulty ends up right? It could be more or less when it settles. You assume the exact same miners from prior to the NFactor change. I say more, new miners will jump on board--optimism.
I think you're overly optimistic - with the way the hashrate fell for all cards that aren't 4GB cards, I would make you a gentlemans wager that we're going to see it below 50% what it was a week ago (1.08k per the mining software, 0.0164 difficulty). If we settle above 500/0.0763 I would be shocked. My best cards dropped 60%, my worst 70% and I'm going to hypothesize that all CPU's dropped by 50%. So, unless, as you say, there is an influx of new miners, a 60%+ drop in difficulty should not be a surprise.