BIGTREETECH CB2
The BTT CB2 upgrades the CB1 with a Rockchip RK3566 quad-core Cortex-A55 at 1.8GHz, 2GB RAM, 16GB onboard eMMC, and Gigabit Ethernet in the same CM4 form factor. At $45, it doubles the RAM and adds onboard storage, making it the better choice for Klipper hosts running webcam streaming or multiple services.
The CB1's faster successor — worth the extra $10 for 2GB RAM and Gigabit Ethernet.
Where to Buy
Pros
- 2GB RAM provides comfortable headroom for Klipper + webcam + timelapse processing
- Rockchip RK3566 Cortex-A55 at 1.8GHz is 20% faster per-core than the CB1's H616
- 16GB onboard eMMC eliminates microSD card reliability issues
- Gigabit Ethernet for fast G-code file uploads and webcam streaming
Cons
- At $45, it costs $10 more than the CB1 — meaningful on tight budgets
- Still requires a CM4-compatible carrier board — no standalone use
- 2GB RAM is half of a Raspberry Pi 4 4GB — not enough for heavy multitasking
Performance Upgrade Over CB1
The Rockchip RK3566's Cortex-A55 cores at 1.8GHz offer approximately 20% higher single-threaded performance compared to the CB1's Allwinner H616 Cortex-A53 at 1.5GHz. While Klipper itself is not CPU-bound on either chip, the difference shows up during input shaper analysis, timelapse rendering, and web interface responsiveness under load.
The 2GB RAM is the more meaningful upgrade. Klipper + Moonraker + Mainsail consumes about 600-700MB, leaving 1.3GB free on the CB2 versus only 300-400MB on the CB1. This headroom matters when adding crowsnest for webcam streaming (100-200MB), timelapse plugins (variable), or running multiple printer instances from one host.
Storage and Connectivity
The 16GB onboard eMMC is a significant reliability improvement over the CB1's microSD-only storage. MicroSD cards in always-on printer hosts are prone to write-wear corruption, especially during unexpected power loss. eMMC has better wear leveling and higher write endurance. The CB2 also supports a microSD card for expanded storage or as a boot fallback.
Gigabit Ethernet replaces the CB1's 100Mbit Fast Ethernet. For uploading large G-code files (some complex prints exceed 100MB), Gigabit reduces transfer time from 8+ seconds to under 1 second. Webcam streaming at 720p or higher also benefits from the increased bandwidth. Onboard WiFi is available but wired Ethernet is recommended for reliability in enclosed printers.
Full Specifications
Processor
| Specification | Value |
|---|---|
| Architecture | ARM Cortex-A55 |
| CPU Cores | 4 |
| Clock Speed | 1800 MHz |
Memory
| Specification | Value |
|---|---|
| ram_gb | 2 GB |
| storage | MicroSD + 16GB eMMC |
Connectivity
| Specification | Value |
|---|---|
| WiFi | 802.11 b/g/n/ac |
| ethernet | Gigabit Ethernet |
I/O & Interfaces
| Specification | Value |
|---|---|
| USB | 2x USB 2.0 + 1x USB 3.0 |
| display_port | HDMI |
Physical
| Specification | Value |
|---|---|
| Dimensions | 40 x 55 mm |
| Form Factor | CM4-compatible SBC module |
Who Should Buy This
The 2GB RAM handles Klipper, Mainsail, Moonraker, and crowsnest webcam streaming simultaneously without swapping. The CB1's 1GB RAM leaves only 300MB free after the Klipper stack, which is tight with a webcam.
The CB1 at $35 runs Klipper + Mainsail just fine if you skip webcam streaming. Save the $10 if you do not plan to add a camera or timelapse plugin.
Better alternative: BIGTREETECH CB1
2GB RAM is workable for light Home Assistant add-ons but not a full HA installation. For running Home Assistant alongside Klipper, a Raspberry Pi 4 with 4GB+ RAM is recommended.
The CB2 requires a CM4-compatible socket. For standalone use with USB and HDMI, the BTT Pi V1.2 at $30 works with any mainboard via USB.
Better alternative: BIGTREETECH Pi V1.2
If configuring firmware and wiring stepper drivers feels like a lot, the Bambu Lab A1 Mini prints out of the box for under $200.
Better alternative: Bambu Lab A1 Mini
Frequently Asked Questions
Is the CB2 worth $10 more than the CB1?
Yes, if you plan to use a webcam or timelapse plugin. The 2GB RAM and Gigabit Ethernet handle these workloads comfortably. If you are running Klipper only with no webcam, the CB1 at $35 is sufficient.
Does the CB2 have onboard WiFi?
Yes. The CB2 includes onboard WiFi, unlike the CB1 which requires a USB dongle. However, wired Ethernet is recommended for Klipper reliability, especially in metal printer enclosures that can interfere with WiFi signals.
Can the CB2 replace a Raspberry Pi CM4?
Physically yes — it uses the same CM4 connector. Software compatibility depends on the carrier board. BTT officially supports it on the Manta M8P and M5P. Raspberry Pi OS does not run on the CB2; use BTT's MainsailOS image instead.
What operating system does the CB2 run?
BTT provides a Debian-based MainsailOS image with Klipper, Moonraker, and Mainsail pre-installed. You can also install Armbian for more flexibility, though you will need to install the Klipper stack manually.
Is 16GB eMMC enough for Klipper?
Yes. MainsailOS with Klipper uses about 4GB. The remaining 12GB stores G-code files and timelapse videos. For users with large G-code libraries, add a USB flash drive or network-attached storage.
Should I get the CB2 or a Raspberry Pi 5?
Get the CB2 if you have a Manta M8P and want clean integration at $45. Get a Raspberry Pi 5 if you want 4-8GB RAM, better GPIO support, standalone operation, and the ability to use it beyond 3D printing. The Pi 5 costs $60-$80.
Can I run two printers from one CB2?
Yes. Klipper supports multiple printer instances on one host. With 2GB RAM, two printer instances plus Mainsail is feasible. Three or more printers may cause memory pressure depending on the plugins you run.