so far Supermicro hasnt supported Ryzen AM4 , only threadripper and Epyc cpu's... will be VERY surprised if they support AM5ASRock, Supermicro, ASUS will all have bare bones servers for the AM5 platform, probably Q1.
Looks like about $500 and available in a month or so. Might be easier searching on alibaba or something though.BEHOLD
My best guess is trace lengths. The 10GbE controller is right next to the CPU socket, whereas the chipset is on the other side of the board, near the x4 slot.Gigabyte made odd choices. The biggest is that they are using one of the CPU's PCie x4 ports for the 10GbE controller. If my math is right, 2x 10GbE is ~ 2.5GB/s. Those x4 lanes are PCIe 5.0 from the CPU so this controller is only using ~16% of the bandwidth. Meanwhile, they are hanging a PCIe 4 x4 slot off of the B650 chip which has to share the PCIe 4 x4 link to the CPU. Seems to me that they should have hooked the 10GbE controller to the B650 chip, since it would use less than half the bandwidth to the CPU and used the x4 off the CPU for the x4 slot.
Not splitting the x16 -> x8 + x8 is also unfortunate. Lots of odd I/O choices on this board. Hopefully ASRock Rack will do a little better.
Good luck buying that anywhere!!