GTX 1070s - they're more cost-efficient.
Or Titan X Pascals - the ultimate folders regular people can get.
Rate: 6 1080s = 6 1070s PLUS 1 980Ti (or even 1 TitanX)
Energy: 7 cards vs 6 to save ~30 watts
Past a hobby rig, whatever "savings" you have are lost in more risers and PSUs.
I'll keep the good stuff, thanks.
https://docs.google.com/spreadsheets/d/1vcVoSVtamcoGj5sFfvKF_XlvuviWWveJIg_iZ8U2bf0/pub?output=html#Much more accurate info using REAL folding of REAL units than the benchmark, which only tests specific aspects of folding one at a time.
Depending on WHICH benchmark aspect you look at, the Nano should be directly competative to the GTX 1070 on performance - but in real folding work it's quite a bit worse.
Also, the COST of those 1080s is what I was talking about - energy efficiency is going to be pretty much a tossup either way, but paying more than 50% more for the cards for perhaps a 20% PPD improvement is NOT cost effective.
Try finding a 1080 in an ITX form factor short card like the Gigabyte (I build 3 card rigs, but due to limitations of available motherboards I need a short card to allow for decent cooling of all 3 cards).
I supposed I COULD use 2x 1080 and a single 1070 though, so that point is a strawman argument to a degree.
The Titan X Pascal is also less cost-effective, though it earns enough more in bonus PPD it might be better on a PPD/watt basis.
It is NOT cost effective on a PPD/$ basis even vs the 1080, much less the 1070.
980 ti aren't worth buying any more, unless you can get a used one fairly cheap.
Dunno why you included THAT in your comparison - that IS a strawman argument.
I don't do riser rigs - have had too many issues with the bloody things back in the days I DID use them.
2 x 3 card no riser rigs aren't much more expensive IF at all than a single 6 x riser rig - you can use smaller much less expensive PS (cost per watt on a PS is pretty much even for quality Gold rated supplies 'till you hit the 1000 watt ballpark, at which point it starts climbing pretty fast), you DO take a hit on the HD/SSD/Pen Drive + RAM + CPU doubling up, but you might make that up on the LOW COST very common motherboards for 3 slots vs the rather HIGH price very limited selection of motherboards that can handle 6, and you DEFINITELY make up some on not needing risers.
It's also a lot easier to get a 3 card rig to work in the first place, though once you get a rig to work at all it's not hard to "clone" it if you're running Ubuntu/Xubuntu - would be trivial if Ubuntu/XUbuntu used LILO instead of that PITA Grub bootloader with it's usage of that stupid majorly irritating UID garbage instead of standard drive designations.
Non-riser machines also tend to be more reliable, and if you have a riser rig go down you lose ALL of the production from it vs. half if you have 2 x non-riser machines and one goes down.