Stefan Mileschin

ASUS has announced the latest addition to its mining motherboards with the H370 Mining Master. This ATX sized board will support up to a mind-boggling 20(!) graphics cards via USB riser cables plugged directly into the PCB. Outside of an obvious benefit of increased density, ASUS says this setup can also minimize downtime by making problems easier to diagnose. The USB setup is said to allow miners to allocate more hardware and power budget to the GPUs doing the work rather than the infrastructure to support it. ASUS will be displaying a setup with this board at Computex using 12 Radeon RX470’s and eight NVIDIA GeForce P104 cards.

One of the first things one will notice on the board are the 20 USB 3.0 ports where one would normally see PCIe slots of varying sizes (on a mining motherboard, usually x1 slots). About the most we have seen in an ATX form factor is 18 in ASUS’ own B250 Mining Expert. The banks of vertical USB ports are said to be sturdier than a PCIe card and enables cleaner wiring and less clutter around the motherboard.

The board is able to support so many USB interfaces as crunching crypto blocks does not require a lot of interface bandwidth. Each card will use a PCIe x1 link which is routed over USB 3.0 wiring (USB 3.0, like PCIe, being a differential signaling bus). There are a few UEFI tweaks that are found in a special Mining Mode to help with efficiency. For example when in mining mode, the motherboard’s PCIe lanes run at Gen 1 speeds for improved compatibility and stability when using USB riser cards. Above 4G decoding is enabled which assists with supporting a lot of video cards as well as Launch CSM being disabled letting the board and GPUs UEFIs synchronize with each other avoiding firmware changes.

https://www.anandtech.com/show/12840...-gpus-over-usb