Update: The Compute Module 4S is now listed on Raspberry Pi's website . But they state it "is not for general sale."

Strange times beget strange things.

And that's an apt description of the new Raspberry Pi Compute Module 4S:

The above chart is from Revolution Pi's page announcing the RevPi S and SE , which are updates to their popular CM3+-based industrial DIN rail computers.

They've been working on a RevPi 4 built around the Compute Module 4 that was announced in 2020, but after many delays, it seems they brokered a deal with Raspberry Pi to use a cut down Compute Module 4S, which eschews not features like gigabit Ethernet and PCI Express, as well as the entire form factor of the CM4.

The CM4S mashes a BCM2711 SoC into the Compute Module 1, 3, and 3+ form factor—which was used for years until the switch to 2x 100-pin board-to-board connectors on the CM4 (pictured on the left):

I'm guessing the reason this board was produced is because Raspberry Pi can't secure enough of the older 40nm process SoCs that powered older-generation Pis.

Instead of leaving industrial customers who designed around the old SO-DIMM form factor out to dry, they updated the design to use the 28nm BCM2711, which does seem to be available in quantities surpassing 500,000 per month currently .

So far, I don't know if the CM4S will be made available to anyone outside of Revolution Pi, though I've posted on the forum asking as much: New Compute Module 4S? [Raspberry Pi Forums] .

While the CM3+ and earlier Compute Module models weren't quite as popular as the CM4 is today (owing to their slower SoCs and weaker IO), they are in a lot of embedded devices. I'm sure many customers would love a drop-in upgrade to the BCM2711, with it's doubled CPU performance, faster GPU, and doubled memory bandwidth.

For a little more detail on the CM4S, check out my latest YouTube video, embedded below: