QuantaGrid D51B-1U is a general -purpose rackmount server designed for optimal performance and power efficiency. It is based on the dual Intel® Xeon® processor E5-2600 v3, v4 product family and features up to 1.5 TB memory capacity in a 1U chassis.
They have 3b10.01 and 3b09.01 bios downloads available.
I suspect that the CPLD update in the "v4 update package" may be necessary to support v4 cpus, above and beyond needing a 3b bios version.
Still testing on this.