Power in a Tiny Package: A Hands-On Review of the Raspberry Pi Compute Module 5

It's been a little over four years since the Raspberry Pi Compute Module 4, the computer-on-module inspired by the Raspberry Pi 4 Model B single-board computer, hit the market — and just over a year since the launch of the Raspberry Pi 5. That Raspberry Pi was working on a successor to the former based on the latter is no secret, and now that successor is here: the Raspberry Pi Compute Module 5.

Available in a variety of configurations, from 2GB of RAM and no eMMC all the way up to 8GB of RAM and 64GB eMMC (with a hint on the board of a possible 128GB eMMC model to follow, and promises of a future upgrade to 16GB too), the Compute Module 5 brings the power of the Broadcom BCM2712 to the computer-on-module form factor for the first time.

But does it live up to four years' of hopes and dreams? Read on to find out, as we go hands-on with the Raspberry Pi Development Kit for Compute Module 5.

The hardware

• CPU: Broadcom BCM2712 4-core up-to-2.4GHz Arm Cortex-A76 (16nm)
• GPU: Broadcom Videocore-VII
• Hardware video decode: H.265 4k60
• Hardware video encode: None
• "Southbridge" chip: Raspberry Pi RP1 (40nm)
• RAM: 2GB, 4GB, or 8GB ECC LPDDR4x at 4,267MHz, 16GB in early 2025
• Storage: 16GB, 32GB, or 64GB eMMC (CM5 Lite 0GB eMMC, SDIO)
• USB: 2× USB 3.0, 1× USB 2.0
• PCI Express: 1× PCI Express Gen. 2
• Network: Gigabit Ethernet PHY with Precision Time Protocol (PTP), optional dual-band 802.11ac Wi-Fi, Bluetooth 5.0, Bluetooth Low Energy (BLE)
• Display outputs: 2× 4k60 HDMI, 1× DPI parallel display, 2× four-lane MIPI DSI (shared with CSI)
• Camera inputs: 2x four-lane MIPI CSI (shared with DSI)
• GPIO: Up to 30× GPIO pins, 5× UART, 5× I2C, 1× I2S, 4× PWM channels, 3× GPCLK outputs
• Power: USB Power Delivery over USB Type-C at 5V 5A
• Size: 55×40×4.7mm (around 2.17×1.57×0.19")
• Cost: From $45 (CM5 Lite 2GB, CM5002000) to $95 (CM5 8GB/64GB with radio, CM5108064) module-only; CM5 IO Board $20, CM5 IO Case $15, Cooler for CM5 $5, Antenna Kit $5; $130 for the Raspberry Pi Development Kit for Compute Module 5 (as reviewed)

If the Raspberry Pi Compute Module 5's specs list looks familiar, there's a reason for that: it's effectively most of a Raspberry Pi 5, launched back in September last year, in a smaller form factor. It uses the same Broadcom BCM2712 system-on-chip, with the same four Arm Cortex-A76 processor cores running at up to 2.4GHz and the same Videocore-VII graphics processor. It even has the same in-house RP1 peripheral controller, responsible for the general-purpose input/output (GPIO) pins.

There are, of course, differences. The biggest is the loss of physical ports, entirely understandable given that the Compute Module 5 is a computer-on-module; connectivity is instead routed to two high-density connectors on the underside, physically compatible with those of the earlier Compute Module 4 but with a revised pinout to route an additional two USB 2.0 ports. If you want to actually use any of the listed features, the module alone isn't enough; remember to budget for, or build, a compatible carrier board.

A bigger change can be found in the RAM module. Like the Raspberry Pi 5, the Compute Module 5 is available with 2GB, 4GB, or 8GB of LPDDR5 memory — but unlike the Raspberry Pi 5 this is Error Correcting Code (ECC) RAM, which can detect and correct bit-flip errors on-the-fly. There's also been mention of a surprise late-launch configuration, due early 2025: Compute Module 5 variants with a whopping 16GB of RAM, double the previous upper limit.

Given the similarities between the Raspberry Pi 5 and the Compute Module 5, it seems likely that a non-ECC 16GB RAM module will also reach the full-size model at some point — though whether it will land before or after the 16GB Compute Module 5 variants has yet to be announced by Raspberry Pi.

The bundle

The version on test for this review is the CM5104032, with 4GB of RAM, 32GB of eMMC storage, and the optional radio module, provided as part of a new bundle dubbed the Raspberry Pi Developer Kit for Compute Module 5. This brings together the module itself, the new Compute Module 5 IO Board carrier, and one each of the various accessories also launching today: an official case for the IO Board with integrated fan, a passive heatsink for the Compute Module 5, dipole antenna and pigtail, a 27W USB Type-C PD power supply, two HDMI cables, and a USB Type-A to Type-C cable.

It's designed, in short, to deliver everything you need to get started with the Compute Module 5 and its IO Board — just add keyboard, mouse, and a monitor or two, plus a jumper for when you want to flash the eMMC. It also doubles as a jumping-off point for your own designs: as with the Compute Module 4 IO Board, Raspberry Pi has released the PCB design files for the Compute Module 5 IO Board for you to use as a template for designing custom carrier boards.

The inclusion of not only a passive heatsink but an active fan in the bundle may surprise those coming from the Compute Module 4, but not anyone who has experimented with a Raspberry Pi 5: the new Broadcom BCM2712 offers three or more times the performance of the BCM2711, draws more power, and generates more heat. There's less PCB to sink that heat, too, and with only the high-density connectors between the two little is bled off into the larger IO Board: in free-air stress testing, with neither the heatsink nor the fan, the module's PCB hit 75°C (167°F) while the IO Board remained below 40°C (104°F).

The case is perfectly sized for the IO Board, which brings out the Compute Module 5's high-density connectors to more familiar ports — including a Raspberry Pi HAT+-compatible 40-pin general-purpose input/output (GPIO) header, and a Power-over-Ethernet (PoE) header compatible with the existing Raspberry Pi PoE HAT+. There are only two USB ports, both USB 3.0 Type-A, aside from the USB Type-C power input, a gigabit Ethernet port, microSD slot that is disabled for anything other than the eMMC-free Compute Module 5 Lite models, and a Raspberry Pi 5-like power button.

The IO board also exposes the Compute Module 5's PCI Express Gen. 2 lane, though not as a full-size PCIe slot; instead, it's the same M.2 M-key connector you'll find on the Raspberry Pi M.2 HAT+ — though with expanded mounting points supporting 2230-, 2242-, 2260-, and 2280-format M.2 modules. These could be high-speed Non-Volatile Memory Express (NVMe) drives, accelerators for machine learning and artificial intelligence at the edge, or even third-party breakouts to allow for full-size PCIe add-in boards to be used. Finally, there's a CR2032 battery holder for the real-time clock and two HDMI ports — full-size, rather than the micro-HDMI ports on the Raspberry Pi 5.

The Antenna Kit, meanwhile, is the same as was already available for the Raspberry Pi Compute Module 5, connecting to a compact U.FL connector on the module itself — with an electronic switch allowing the Compute Module 5 to switch between external antenna or on-board PCB trace antenna.

The case, as you'd expect, includes a hole into which the antenna mounts, a necessity as the metal chassis blocks signals to and from the module's PCB antenna, along with slots through which the flat flexible circuit (FFC) connectors for MIPI CSI cameras or DSI displays can be routed. The bundled power supply is the same model as already sold for the Raspberry Pi 5 — and the cables are just cables, albeit high-quality ones engraved with the Raspberry Pi logo.

Performance

If you've read our hands-on testing of the Raspberry Pi 5, then there'll be nothing to surprise you here. The Broadcom BCM2712 at the heart of the Compute Module is identical to the one found on the Raspberry Pi 5, and for all their differences in appearance and physical layout the two devices perform near-identically.

The biggest difference is in the use of ECC RAM on the Compute Module 5, which is generally held to perform slightly slower than the non-ECC RAM used on the Raspberry Pi 5 — but we're talking fractions of a percentage point, here, and nothing that should give even memory-hungry workloads cause for concern. It certainly wasn't something our benchmarking could distinguish from the standard margin of error.

The use of the same BCM2712 chip does, however, mean that the criticisms from our Raspberry Pi 5 review apply equally to the Compute Module 5. The biggest of these, particularly for those working on computer vision projects, is the loss of hardware video encode. While the BCM2711 on the Raspberry Pi 4 and Compute Module 4 has hardware video encoding blocks that operate independently of the CPU cores, the BCM2712 does not.

Raspberry Pi excuses the loss of hardware encode with the fair observation that the BCM2712's CPU cores are considerably more powerful than those of its predecessors, and easily capable of real-time video encode in software; that does mean that at least some of the CPU power is no longer available for other workloads while it's being used to encode video.

Anyone who has been working with the Compute Module 4 will be wondering if it's worth the upgrade. The answer in almost all cases is yes: the Compute Module 5 is considerably more powerful than its predecessor, showing a tripling of performance in many real-world workloads. One feature that will be of particular interest to those working on Internet of Things (IoT) projects is the addition of cryptographic acceleration instructions: AES encryption and decryption perform around 12 and 19 times faster respectively on the Compute Module 5 than the Compute Module 4.

There is, of course, a catch: while the Compute Module 5 looks like it should be a drop-in replacement for the Compute Module 4, the extra performance is tempered by a hungrier power draw. Previously, carrier boards were typically designed around a 5V 3A power supply expectation; the Compute Module 5, like the Raspberry Pi 5, needs more overhead with a 5V 5A supply — though, again like the Raspberry Pi 5, will operate with a 3A supply if required, so long as you're not using too many high-power peripheral devices.

Thermals are also a consideration when moving to the Compute Module 5. The development kit comes with a near-full-coverage heatsink and a fan in the case for a reason, and without them you'll see the Compute Module 5 begin to throttle its CPU speed within about 25 seconds of starting sustained all-core compute. Even then, though, the Cortex-A76 cores are running at 1.5GHz and will equal or even beat the performance of a Compute Module 4 running un-throttled.

Neither the passive heatsink nor the IO Case's fan alone, sadly, are enough to keep the BCM2712 from throttling in an all-cores torture-test scenario — and Raspberry Pi's packaging for the kit warns that the heatsink is "not designed for use with IO Case lid." There's also a minor bug in the fan's handling: while it's speed-controlled with the Compute Module 5 booted up, shutting the module down while keeping the power live makes it spin at full speed until you hit the power switch to boot back up again.

Conclusion

If you're building around a Raspberry Pi Compute Module, there's little reason to stick with the older Compute Module 4 family — unless you're optimizing for a limited peak power draw, or need the hardware video encode blocks missing from the new GPU. The Compute Module 5 is considerably faster than its predecessor, and the additional USB lanes will appeal to those looking to put it at the heart of something with plenty of peripherals.

The other reason to stick with the Compute Module 4 would be price. The Compute Module 5 is, unsurprisingly, more expensive at the lower end of the range — even before you factor in anticipated discounts as resellers look to reduce their stock of the older models.

The cheapest model of Compute Module 4, the CM4001000 (CM4 Lite, 1GB RAM), launched at just $30 with the double-the-RAM CM4002000 (CM4 Lite, 2GB RAM) priced at $35; the cheapest Compute Module 5, the CM5002000 (CM5 Lite, 2GB RAM) is $45, a ten-buck premium. Ten dollars isn't much, true, but you'll almost certainly want to add at least the Raspberry Pi CM5 Cooler to your bill of materials — bumping the price up by another $5 on top. For that you get a rough-trebling-or-better of performance, which for all but the most cost-conscious design has to be seen as the bargain it is.

The price premium disappears when you go up-market: the range-topping CM5108064 (CM5, 8GB RAM, 64GB eMMC) is the same $95 as the CM4108032 (CM4, 8GB RAM, 32GB eMMC) launched at, despite having double the eMMC storage.

Thermal performance, though, is an issue — unsurprising, given that it's an issue for the full-size Raspberry Pi 5, too, despite its larger PCB. Neither the passive heatsink nor the active fan in the IO Case are enough to let the CPU and GPU run at full tilt for more than half a minute or so before it's thermally throttled, and you're not able to use the two together for boosted cooling.

The Raspberry Pi Compute Module 5 is now available to order from Raspberry Pi resellers, and will remain in production until at least January 2036.