Raspberry Pi CM3E joins CM4S in the old SO-DIMM form factor

Last week this Tweet crossed my timeline:

Just taken delivery of a shiny @wallboxchargers EV charger and spotted the super shiny new @Raspberry_Pi CM3E in there with its super swanky combined CPU/RAM package 😎 pic.twitter.com/oEUqKPMwTK

— Pi 0 in your Pocket (@Pi0CKET) June 9, 2022

If you look closely, that's a "Raspberry Pi Compute Module 3E"—which is so far not listed on Raspberry Pi's website.

This Pi joins the mythical Compute Module 4S as one of two Pi models mere mortals are unable to obtain—believe me, I've tried. The folks at Pi HQ in the UK apparently don't even have them on their shelves. The CM4S is at least listed on Raspberry Pi's website now, though with the following note:

Based on the Raspberry Pi 4 Model B architecture, Compute Module 4S is intended for specific industrial customers migrating from Compute Module 3 or Compute Module 3+ and is not for general sale.

If you look closely at the CM3E, the SoC on the board is an RP3A0-AU. That's the same chip from the Raspberry Pi Zero W 2 introduced last year.

Raspberry Pi has had to shift parts around and rely on some previously-shelved designs, it seems, to fulfill industry orders for devices that integrate the 200-pin SO-DIMM form factor that was used by the CM1, CM3, and CM3+ models. It would seem stocks are running low on SoCs like the BCM2837 used in the prior Compute Module revisions.

Apparently there was even a CM2 in the works at some point, but I doubt that'll come back from the dead, since that SoC was the last in the Pi lineup without 64-bit support!