The Raspberry Pi Compute Module 4 introduced both a new form factor and a PCIe 1x connection which has seen use with M.2 expansions for storage and Tensorflow Processing Units. Wiretrustee has taken the initiative and created a NAS carrier board that provides space for up to four SATA drives.
Wiretrustee's SATA Board for Raspberry Pi Compute Module 4 measure just 4 inches square (100 x 100mm), and on the top of the board we see four SATA power and data interfaces angled so that the drives are vertical. These four drives are linked to a Marvell 88SE9215 SATA-to-PCIe interface. At this time, Wiretrustee have tested the SATA ports, and in a Reddit post they have discussed their progress including SATA drive speeds, which are nothing to write home about but it is still early days.
"We've tested it with the Raspberry PI OS and it has a write speed of ~220MB/s on each of the SATA ports (not simultaneously of course)".
On first glance, we instantly noticed that there was no space on the board for the Compute Module 4. Rather than create a board with a larger footprint, they have cleverly located the CM4 on the underside of the board. The board has connectors for 12V power input and a 12V 4 pin fan connector, useful to keep the CM4 and drives cool if used in an enclosure. An LED control board, broken off from the mainboard, shows drive activity and provides useful power and reset buttons.
Looking around the board we can see a Gigabit Ethernet port, two USB 2.0 ports, a single HDMI 2.0 port and USB-C power for the CM4. A microSD can be used as a boot device, but you can also use a CM4 with onboard flash storage as a boot device.
It is still early days for this project, and it is still under heavy development with a testing schedule currently underway. There is no word on price or release date, but Wiretrustee intend to offer the board via Crowd Supply.
