love my onda b250 d8p v1. will never build a riser rig again.
some of those riserless boards have better slot spacing than others, the d8p v1 is very good with 2.5 spacing. i dunno how well a 2.0 spacing board will do cooling wise.
but the d8p with its 2.5 spacing will not fit in a server case whereas a board with 2.0 spacing would.
one thing i will always want in a riserless board is a socket for the cpu rather than a built in. just personal preference.
Yep, I have been adding cards to my 2nd Onda D1800 6-GPU mobo as I get them in and I really like these boards, BUT....
The 5cm PCIe slot spacing on my D1800's is just too close to allow the GPU fans to pull in enough air, and I am not running terribly powerful cards in either rig. One D1800 is kitted out with RX 560s and they aren't such a problem - only 75W max TDP and a bit thinner, too - but the other one is loaded up with GTX 1060s and it has been a real struggle to keep the first 5 cards cool (the last one is fine since its fan is unobstructed).
The Celeron CPU is also woefully underpowered - you pretty much have to stop mining if you need to interact with it at all. I'm not saying it needs an i5 or a Ryzen or anything, but even something about 2x faster would be a tremendous improvement. That said, the wimpy CPU is a main reason why the mobo only needs about 30W...