Mixtile reveals U.2 to PCIe/SATA breakout board for Rockchip RK3588 cluster

Mixtile Blade 3 is a Rockchip RK3588 SBC with up to 32GB RAM designed for server applications, notably to build clusters through a U.2 edge connector with 4-lane PCIe Gen3, SATA 3.0 to interconnect multiple boards.

What was not clear so far is how multiple boards would be connected, as we were just shown two boards connected by a U.2 cable, which does not scale, and does not provide power as the 12V input also comes with the U.2 connector. The company has now provided more details showing how it’s done, namely through a breakout board that connects to the U.2 edge connector, and allows cluster design as shown below.

Mixtile Blade 3 cluster: boards connection

The U.2 breakout board comes with a 6-pin connector 12V power, pair of SFF-8643 (mini SAS) connectors for PCIe daisy-chaining, and a SATA port. Since short SFF-8643 cables are hard to find, Mixtile will provide custom 15-cm cables with the breakout board. They will also release the pinout so people can make the mini SAS cables themselves if needed.

Mixtile U.2 breakout boardThis type of design should be cheaper and more flexible than having a backplane board with multiple U.2 connectors, albeit not quite as compact, and not suitable for racks. That’s why another solution will be provided for a high-density server that can integrate 75 Blade 3 boards in a standard 19-inch 2U chassis. The breakout board solution should be used in Mixtile Cluster Box on Crowd Supply.

Mixtile Blade 3 U2 breakout boardThat’s for the hardware, and it does not say anything about software, but Martin Liu from Mixtile provided some insights in a previous comment:

RDMA is our further plan. We’re focusing on the IP-over-PCIe driver, which is not that good on the performance but is easier to understand by users and compatible with existing software.

The way I understand it, the IP-over-PCIe driver may create an additional (32Gbps) network interface on the board and allow TCP/IP communication over PCIe. RDMA protocol support may come later. For reference, RDMA (Remote Direct Memory Access) is a technology that enables two networked computers to exchange data in the main memory without involving either one’s operating system.

Via Crowd Supply.

Share this:

Support CNX Software! Donate via cryptocurrencies or become a Patron on Patreon

ROCK Pi 4C Plus
Notify of
The comment form collects your name, email and content to allow us keep track of the comments placed on the website. Please read and accept our website Terms and Privacy Policy to post a comment.
Weller PCB manufacturer