Also, for cooling, there are 4 x 140mm fans which is much more flow area than the 3 standard 120mm fans for most 4U cases. This offers an entire extra fan plus the additional flow capacity of a 140mm fan. It will allow for lower fan speeds and there is a direct flow path between the GPU's and the fans.
It doesn`t matter really. I have 4*120delta in my case with speed regulator. It works about 30-40%. 70% was a maximum in closed room without any hood.