The Raspberry Pi Compute Module 4S is an upcoming system-on-module based on the same Broadcom BCM2711 quad-core Cortex-A72 processor found in Raspberry Pi Compute Module 4, but using the same SO-DIMM connector as found in earlier Raspberry Pi Compute Module boards, instead of the new board-to-board connectors.
The Raspberry Pi Compute Module 4S is not launched yet, but we discovered it will be used on Revolution Pi S and SE series DIN-rail industrial computers via a tweet from Jeff Geerling and his post on Raspberry Pi forums.
Apart from the faster processor and support for 4K video output, The Raspberry Pi Compute Module 4S is quite similar to the Raspberry Pi Compute Module 3+.
Raspberry Pi CM4S
Broadcom BCM2827B0 quad-core
Cortex-A53 processor @ 1.2 GHz with VideoCore IV GPU
Broadcom BCM2711 quad-core
Cortex-A72 processor @ 1.5 GHz with VideoCore VI GPU
Up to 32GB
1x HDMI 1.3a up to 1080p60
1x HDMI 2.0a up to 4Kp60
Up to 350 Mbps
USB 2.0 interface
67.6 x 31 mm
Memory bandwidth might be a little better with the LPDDR4 memory too (TBC), but all the rest looks the same. The main advantage of the new Raspberry Pi CM4S module is compatibility with older SO-DIMM carrier board, and possibly better availability once it’s launched since older 40nm Broadcom processors like the BCM2837 are in short supply. Few people will use it for new designs as memory capacity appears to be limited to 1GB, and you’ll lose the PCIe interface, Gigabit Ethernet, plus support for optional WiFi and Bluetooth found in the Raspberry Pi CM4 module.
Revolution Pi provides further insights into the CM4S module:
As you know, the Revolution Pi family was not spared from the global chip shortage. In the last months we had to put many customers and people interested in RevPis off. This was mainly due to the supply of compute modules, which could not be delivered sufficiently.
The Raspberry Pi organization has therefore offered us a special alternative to the Compute Module 3+: The Compute Module 4S. This is a Compute Module in the form factor of the CM3+, on which the more powerful Arm Cortex-A72 processor of the CM4 is installed.
The following modules will be available as S/SE series: RevPi Core, RevPi Connect and RevPi Flat.
Customers upgrading from the CM3+ module will have to upgrade to a newer Linux 5.10 kernel.
The company says the first units of their S and SE series fitted with the RPi CM4S module will be shipped at the end of April as an alternative to their original orders. New orders should only become available in July 2022. Compute Modules 3 or 3+ based products will remain in their portfolio, and should start shipping again once the Raspberry Pi shortage issues are resolved.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.