Well, I pre-ordered an RPI5. While I’m eagerly awaiting it: have any of the devs received an advanced copy? Would there be any impediment to running the current silverblue aarm64 installers (driver problems, etc?)
Technicalities aside, have you ordered one, and do you plan to run fedora on it? What are you going to do with your project?
As it hasn’t been publicly released yet, I doubt we’re going to really know until it gets here. I’m sure it will eventually be supported, but whether it will support anything but Raspberry Pi OS out of box is something that we’ll likely all find out together.
I’m thinking about supplying it with 5V/5A via the 2 5V GPIO pins and two of the Ground pins.
Does anyone know whether the RPi 5 can supply enough power to supply a couple of 2.5 inch disk drives over its USB 3 connectors, please? Previously, I have had to give the disks their own separate 5V supplies. It seems to suggest that the answer is ‘yes’ here: Raspberry Pi Documentation - Raspberry Pi 5
I cannot answer that directly, but if you were to use SSDs and not HDDs then it certainly should be able to do so.
You also should be able to use the HDDs if you used a powered usb hub.
The documentation indicates that when using the higher power (27W) PS and the proper cables that 5W additional power is provided to usb devices (1.6A total), but it is up to the user to ensure that all devices attached remain within the allotted power total. It also states that using the higher power PS but standard usb power cables still limits the device to the standard 15W power.
I don’t know how the power from the gpio pins would be measured. The docs seem to indicate that is not measured or controlled by the board or firmware so I have no way to estimate the results. It does, however, seem to indicate that power from the POE hat pins would be handled similar to power from the usbc power port.
Thanks, Jeff. From what I can tell my Seagate 5TB disks use 0.85A, so 2 of them would be 1.7A.
That looks a little bit close to the edge, to me.
I also wonder if the spin-up current might at least sometimes be higher than 0.85A.
In case anyone is reading this and wondering, it is actually very easy to supply hard disks with extra 5V when they are attached to USB 3.* cables. You just cut through the 2 layers of outer cable, find the really fat red and white conductors, sever them, then solder on wires for a separate 5V supply. The red wire from the RPi must be unattached. They all need to be insulated of course. And the whole bodge can be protected from EMI by wrapping aluminium tape around the joint. The tape makes the joint very strong, but leaves it inflexible. Do not use an eBay 5V supply, but get a Meanwell one from somewhere. This way is cheap and compact; there are many other ways too …
That would be beyond the documented 1.6A available power. Additionally that 1.6A is documented as the maximum combined for all usb devices attached.
A simpler and less risky method of doing the external power for the SSDs would be a simple USB enclosure for the drive with its own power supply. Yes, a user can do that kludge, but safer and easier to use an enclosure with its own power supply and each only costs about $12 to $25.
If you were to use only one drive at a time the Pi should have enough power for it without external power. On my system, with my media server and over 400 movies as well as over 1000 mp3s I only use ~4.5TB of space. A single 5T Bdrive would be adequate for that data.
The problem is not power consumption or suppy (this can be adjusted in the config.txt).
The problem will be booting Fedora as the device tree does not contain chip-specific boot code.
I’m not saying it won’t support the Pi5, but there is a lot of work left until support is possible. That’s why I guess support is not happening any time soon.
Fedora uses the upstream kernel with little or no modification. So as long as the upstream kernel does not support the Pi5 chips, Fedora can’t support it.