Anyways, I think focusing on the riserless mobos is better strategy moving forward. Save money on unreliable risers, better heat control and lessen OS compatibility issues.
I love the sound of eliminating risers if possible. Just the time saved troubleshooting the rig if it's acting up would be pretty valuable, even without the additional cost savings. I hope that somebody makes one with ample enough spacing to run a full 6-8 higher wattage GPUs, such as GTX 1080 Ti, Rx Vega etc.
i don't get what citronick is saying about "better heat control" but risers are imoprtant to make space between hot gpus, the closer they are together the hotter they get..
quality risers are good, most of my risers from late 2013 are still going strong.
The non-powered ribbon style risers do work nicely especially if they are well made. However, with newer GPUs requiring more power, the newer risers that have voltage control, better capacitors and 6-pin power (v6c/v7c?) is the gold standard for riser based rigs. Avoid the molex powered risers or any of the v1 to v5 risers.
Better heat control can be achieved more efficiently with riser less mobo builds, using in conjunction with powerful "Scythe" fans placed back and/or front of the cards depending on reference/blower GPU or otherwise. If done properly, you could get 1080tis with paper thin spacing at beast mode and still attain acceptable temps.
Currently, I use a "vertical GPUs on S hook design" for the RX ETH farm and also using zip-ties for the newer builds on TB250s and H110s....
I will try and get some pictures to show my experiments in the warehouse..... but my group members is kind off anal about showing pictures of the farm.... but will take some discreet shots.
that cooling solution might be enough for the place/country you are mining but other countries/places that tend to be hotter than yours, that setup might not be good enough for them..
regarding "Scythe" fans or any solution like that....that's basically blowing the heat in tight spaces between gpus, heating the room and then exhausting the heat from the room to outside..that is... GPUs--->small fans---> room exhaust (3 step cooling)
for me it is better to make wide space between cards (no need for "Scythe" fans or any solution like that), the room heats up and then you exhaust the heat from the room, this way it is more simple and less energy/fans/effort used....that is.. GPUs-->room exhaust (2 step cooling)
that "small fans" solutions for me is just a remedy to certain areas/situations in my mining room where temps tend to become hotter (places where it is getting crowded and cards get uncomfortably hotter)...
i totally agree with your setup if risers are pain in the ass for you and the country/place you are mining is advantageously cool enough.
just think of it..you underclock/run a GPU in its most efficient power tune/bios mod to become power efficient overall and save power(hashes per watt)...and then you add a 6w fan as an additional power consumption.