The Raspberry Pi Foundation has announced the launch of the long-awaited Compute Module 3, adding 64-bit and multi-core functionality to the compact computer-on-module (COM) design for the first time.

Launched in April 2014, the original Raspberry Pi Compute Module took the single-core ARMv6 BCM2835 system-on-chip (SoC) of the credit-card size Raspberry Pi Models A and B and plonked it on a tiny SODIMM-layout module. Designed primarily for industrial use, the Compute Module saw modest adoption before the launch of the Raspberry Pi 2 brought the BCM2836 and its quad-core ARMv7 CPU. Oddly, the Compute Module ended up being left behind: While those using the larger Raspberry Pi models could use a wider range of software, enjoy more memory, and run four threads simultaneously, Compute Module implementations were left with more limited software support, half the memory, and only one thread at a time.

When the Raspberry Pi 3 launched with the yet-newer BCM2837, a quad-core 64-bit ARMv8 part, the Compute Module looked even more dated - but the Foundation promised that a hardware refresh was coming. Now, that refresh is here with the announcement of the Compute Module 3.

Skipping entirely over the number two, the Compute Module 3 is essentially a cut-down Raspberry Pi 3: the same BCM2837 chip is featured with 64-bit support, along with 1GB of RAM and 4GB of onboard eMMC flash storage - something missing from its full-size equivalent. For those who don't need local storage, a Compute Module 3 Lite drops the eMMC flash in favour of the ability to wire up your own storage on the edge connector pins.

Missing from the Compute Module is the Raspberry Pi 3's radio module, which provides Wi-Fi and Bluetooth connectivity. Dropped, it would seem, for space reasons, the Compute Module 3 will instead rely upon third-party hardware hooked in via the edge connector for wireless or wired networking. The launch also comes along with a new break-out board for prototyping purposes, which supports both the original Compute Module and the new Compute Module 3. Some designs, however, will not support the new board: While a 1mm increase in height is unlikely to cause too many problems, the increased power draw of the BCM2837 SoC means that boards may need to be redesigned and the vastly increased heat output of the chip could cause problems in badly cooled cases.

The Compute Module 3 and Compute Module 3 Lite are, the Foundation has confirmed, to be sold alongside the existing Compute Module which will be retained as a low-power option for those who don't need the increased performance or wider software compatibility. The Compute Module 3 is priced at £29.70, the Compute Module 3 Lite at £24.60, while the original Compute Module drops to £23.40, all including VAT.


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