I’m considering getting a clockworkpi CM4, perhaps with an 8GB non-EMMC CM4, but I would like to use an SSD with it if possible. Did anybody try simply taping a USB SSD enclosure to the case and connecting it to the port, then put /boot on an SD card but the system partitions on the SSD? Does that work at all, does it supply enough power for an average SSD? Does it affect battery runtime in an extreme kind of way, or is it feasible?
Sorry if this was discussed before and I missed the relevant forum thread.
Yes you can put boot on the SD and have the main partition on the SSD. It will use more battery not sure how much you’d lose though. Just make sure you have the fstab set up correctly.
So the output power of the USB port should be enough, even when running in portable mode? I’ve heard that used to be a problem with older Raspberry Pi versions and SSDs.
Update: I found out this may depend on the cells used. I planned to get these so I imagine those would handle higher draw. But that’s assuming the CM4’s battery management system allows it(?). I really don’t know much about this.
So I’ve been testing with a CM5 and an official I/O board for now, and it seems like I need max_usb_current=1 in /boot/usercfg.txt for the SSD to reliably work as a system disk without surprise disconnects that cause the root filesystem to go read-only and the system belly up.
Has anybody tested out whether max_usb_current=1 causes any issues on the uConsole, combiend with a power-hungry CM5 board? I imagine with its built-in power supply, it could hit some sort of limit.
Update: I’ve just realized the CM5 I/O board has usb 3 ports, which is faster than the uConsole. I guess a usb 2 port might lower the SSDs power draw? Very interesting… The big question probably is, what max power draw will the uConsole allow through this usb 2 port? I now asked this here.
So from what I’ve gathered in the other thread, this is probably actually not possible at all with the normal USB port…? Unless perhaps with a kernel I/O throttle, I haven’t found a good one yet.
Update: after some more research, some older SSDs seem to support running with some less power, but the uConsole USB-A limit of apparently ~4 Watt remains painfully low.
For people finding this forum post via a web search: vileer seems to offer an add-on that solves this and makes an SSD work, apparently without power issues. This is not an endorsement since I haven’t tried it out yet.