RPi SATA Adapter: can it power a CM3?

Pretty much what the subject line says, but to expand on that:

  1. Can the existing RPi SATA Adapter properly power the imminent CM3?
  2. If not, will there be a new version of the RPi SATA Adapter that can?
  3. Is there any chance at all of a new RPi SATA Adapter with either a 3rd USB port or an Ethernet jacK?


  1. Should be no problem based on our power design, but we haven’t received a CM3 sample yet to verify.
  2. If for some reason the CM3 doesn’t work, yes, we would update the design.
  3. From a technical standpoint it should be fairly straightforward to do this. It would essentially combine the schematics of our SATA adapter and Smart Cable Module. We haven’t moved forward beyond our current SATA adapter product because the marketability demonstration on the current product has been in limbo due to the “imminent” release of >CM1 over the past 9 months or so. Meanwhile, we’ve been focusing on better packaging and integration of PiDrive and Pi Model-B and Pi Zero.

From your standpoint, what would the main advantages be in a CM-based SATA adapter? Ability to use existing SATA drives? CM upgradability? Form-factor compactness? Orientation/streamlining of I/O connectors? Boot from eMMC? Easy integration of SATA SSD?


Thanks very much for the answers.

As for point one… Have you requested a CM3 from the RPF? I know at least one of their testers (he was testing the camera interfaces) was working with one at least 8 months ago and RPF (per Eben Upton’s comments) was working with NEC for 18 months before their announcement in October. I would think that the RPF would want to help you to be ready when the CM3 launches. In any case, as soon after the CM3 is available and I can afford one (finances are in a black hole at the moment), I’ll test it myself.

On point three. Fair enough, though I would point out that the datasheet for the CM3/CM3L was made public 3 months ago, so the data has been out there that long.

My use case is both pretty simple and probably kind of weird. I’m using a pair of SBCs as a server and a backup server (with a replicated database). At present, I’m using Cubieboards because they have a native SATA-II interface. The primary server has a CD burner attached (via USB ) for taking backups. Both primary and secondary server are connected through a KVM switch. They are both connected to a LAN. This is why I want three connections besides the drive interface.

I very much like the “packaging” of the SATA adapter. I could stack two of them very neatly (which helps when I take everything to the convention where I run Con Reg (see www.dundracon.comhttp://www.dundracon.com). If the USB ports were stacked two high, spacers would be easy to arrange and the magnets would hold everything together.

While I would consider the CM3 sort of adequate, the limitation being that everything is on a USB 2 connection, I look forward to the potential for a future CM to have USB 3 (which will require a board redisgn, as I understand it) and take almost full advantage of SATA III.

I have tested both the 314GB PiDrive and an SSD (using a USB 3 to SATA adapter) with an SBC (Roseapple Pi) that does have USB 3. The PiDrive runs transfer rates around 80MB/s (probably pretty close the drive limit) and an SSD runs around 125MB/s, probably limited by the A9 cores of the Roseapple Pi.

My preference would be to migrate to Raspberry Pis as the software is better and maintained and upgraded (for example, the Roseapple Pi version of Debian does not use EDID to set the screen resolution and changing resolution is a major project in and of itself). The CM3 will have the added advantage of being able to boot over the USB bus, so I could use the CM3L and not need an SD card or eMMC at all.

I can live with 3 USB ports by adding a USB Ethernet adapter (I’ve used one with a CM1 and the SATA Adapter), but to do the full setup, I need 3 ports and the current SATA Adapter only has 2. The SATA Adapter is very close to a fully usable board, but it’s not quite there.

–W. H. Heydt

CM3, CM3L officially released today… Please let us know when the CM3 has been tested with the SATA Adapter.

Yes we saw that announcement and ordered some from Farnell UK, awaiting feedback on stock/delivery. We did request samples earlier but didn’t nag them about it and it may have fallen through the cracks.

BTW, regarding number of USB ports on the SATA adapter, besides Ethernet dongle, what other USB peripherals do you need in your application?


One to go the the KVM switch for keyboard and mouse and one to go to a powered USB hub to handle a CD burner (for backups).

If Farnell can’t do it in a reasonable time, MCM Electronics (they’re in Ohio) claims they’ll have CM3, CM3L and Dev Kits in 10 days (their kit has both a CM3 and a CM3L in it, as well as the CMIO3 board), so they might be an option to keep an eye on. There’s a trick for getting stuff from RS Components in the UK. Use the “rs-export.com” web site and they won’t try to fob you off on their US subsidiary, plus you can set pricing is US$. I hope some of that helps…

–W. H. Heydt

I was going to ask this question, but you’re way ahead of me! I might order an adapter and a board and just hope for the best, I have a project for which a CM3 + SATA-board would fit perfectly.

In essence, I want to build something similar to a WD My Passport Wireless Pro (SD card replication on the run) but with free software and my own control over its functionality. I was going to do it with a PiDrive but I like the form factor of the CM’s and two USB’s are plenty for this. A wifi dongle and SD-card reader and I’m set.:slight_smile:

Why use the CM3? IF you set the OTP bit, you could boot directly from the HDD/SSD using a CM3L. The “boot from USB” appears to be ready to go into general availability with the next release of Raspbian.

That’s a fair point, I like the way you think! I’ll see with availability and pricing which I pick but the more options the better!

I’ve been thinking about some of this stuff for a long time. Long enough to spot most of the opportunities.


Hi, finally received some CM3’s and so far I’ve tested it on our CM-to-SATA adapter and Media Stick and they both work (including CM programming mode on these boards). Next up for validation is our Smart Cable module.

I created a modified version of our Foundation Edition software (our version of NOOBS installer for USB storage) that supports the CM. Here’s a link to the files; they need to be copied to the root directory of the CM’s eMMC (copy the 19 items without the parent folder). This isn’t an official release so please consider it experimental.

I also have a NOOBS-Nextcloud version with CM3 support (it also supports Pi3/Pi2/PiZero). This uses our NOOBS installer to install Nextcloud on the USB drive. Here’s a link to the files- please consider this experimental:

Just for kicks, I tested the CM-to-SATA adapter with our SanDisk 120GB SATA SSD. Boot-up and web-browsing were noticeably sporty!

Here’s a picture:

I have some CM3L’s on order and will try to see if it’ll work with MSD boot (since our adapter boards don’t have a microSD receptacle implemented).


Excellent news. The CM3L should require slightly less power (no eMMC to drive).

Here’s the WD Media Stick with CM3 and WD PiDrive 64GB Flash Drive being powered by the TV’s USB port:

Close up:

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I take it from the pictures that the stick and the SATA Adapter use the same power cirtcuitry.

More on the SATA Adapter…has a test been run in which the OTP bit has been set to permit a CM3L to boot over USB abd then booted directly from an attached SATA drive? (Seems to me to be the obvious way to use the SATA adapter.)

Hi, sorry for the delayed response. I haven’t received the CM3L’s yet so I can’t test out MSD boot. I have CM3’s but the bootcode sees the eMMC and doesn’t try to boot the drive. At least that’s what I think is going on.

When I did the FW update on the CM3 it gave a different output for the command below (part of R-Pi instructions on MSD boot):

$ vcgencmd otp_dump | grep 17:

I don’t know if this is expected, or if MSD boot doesn’t support CM3, or if I may be doing something wrong. I was just planning to try the CM3L as the next step.


I don’t know about the vcgencmd output, but if you delete the files that start the booting process (bootcode.bin?) from the eMMC, one would expect the CM3 to then look for a USB MSD. At least that’s my construction of what should happen. I have a CM3L on order and should have it next week, but almost immediately, I’ll have a convention to run, so it will be at least a couple of weeks before I can play with any of this.

You might consider reporting your results in the sticky thread in the General Forum on the RPF site. Those who have developed the code tend to respond there.

That’s a good idea (deleting bootcode.bin)- I’ll try it hopefully this weekend. Thanks.

Heh… I want this to work because if it does, I’m planning to set up three systems based on a CM3L and the SATA Adapter.

I have my CM3L + SATA Adapter + SSD booting up and running. I used the CMIO3 and an SD to set the OTP bit to support USB booting to MSD. Then, after checking to make sure everything was up to date, CM1 eMMC boot partition copied to the SSD, fstab updated correctly, I swapped in the CM3L and it booted the first time.

I can use the CMIO3 and SD card to set up as many CM3 and CM3L boards as I want, for myself or others. The CMIO3 is acting like a catalyst.

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I finally got around to trying MSD boot on CM3L and only got it half-working. It hangs mid-boot at 17:716127 random: nonblocking pool is initialized. Also, there’s a fairly long delay between powering and when the rainbow screen appears and the booting begins.

When I did program_usb_boot_mode=1, vcgencmd returned 17:3220000a (not 3020000a).

For boot files, I copied them from the latest Raspbian Lite running on a CM3, copied via rsync from the eMMC to the SSD /dev/sda1 (per Gordon’s tutorial).

Any ideas?

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