Supermicro is selling the server below
http://www.supermicro.com/products/system/1U/1027/SYS-1027R-73DBRF.cfm .
Why X9DRD-7LN4F could be used in this same chassis (with CPUs rated up to 135W !) but X9DRH-7TF with 115W CPU cannot be used?"
The X9DRH-7TF motherboard is not recommend because the processor is sit back to back is not best solution in 1U form factor chassis.