2023-09-25 Libre Computer AML-A311D-CC Alta AI SBC Announcement

Libre Computer AML-A311D-CC Alta, part of our Cottonwood family, is our latest performant AI-enabled single board computer designed for compute-intensive applications. With upstream AI and neuro-computing support, this board brings advanced hardware acceleration for the perfect mix of general purpose and specialized computing.

Compatible with SystemReady IR operating systems, Alta incorporates a advanced BIOS compatible with UEFI and supports standard Linux distributions out of the box. It offers seemly hardware migration for existing CC form factor applications that require advanced performance and new capabilities of the Cottonwood platform. It can boot any official Libre Computer image for any board since the BIOS abstracts the hardware behind UEFI.

The board offers industry-leading 1W idle power consumption and can be flexibly powered by USB Type-C, Power over Ethernet, or 5V header directly. For rich IO applications, the performance is similiar to our ROC-RK3328-CC Renegade platform with its Gigabit Ethernet and USB 3.0, although now four ports are exposed via USB 3.0 hub. System wake via UART, IR, button, and GPIO are supported for additional power optimization in constrained environments.

New to the Cottonwood family are MIPI CSI and DSI connectors not found on the Potato family. MIPI connectors follow the 22 pin layout found on the Raspberry Pi Zero W and Compute Module Base IO board for re-use with existing cameras and displays. Combined with the 5+TOPs NPU, Alta is ideal for realtime 4K+ video footage object detection and other modern AI workloads.


  • 4 M Cores
  • 2 E Cores
  • 4 M GPU Cores
  • 5+ TOPs NPU Cores
  • Up to 4GB LPDDR4X
  • USB Type C Power + 2.0 Data Dual Role
  • HDMI 2.1
  • 3.5mm Jack with CVBS and Analog Stereo Audio Output
  • Gigabit Ethernet with WOL
  • 4 USB Type-A 3.0 Hub
  • PoE Connector
  • 40-Pin GPIO Connector
  • IR Receiver Sensor
  • DSI 4-Lane 22-Pin Connector up to 1080P
  • CSI 4-Lane 22-Pin Connector up to 8MP with 2 Cameras
  • 16MB Open Source UEFI BIOS
  • eMMC 5.x Slim Connector
  • MicroSD Card Slot with UHS SDR104 Support

The 40-pin header offers good pinmux coverage for existing peripherals in the Raspberry Pi and CC ecosystems. Additionally, it features numerous I2S, PDM, and TDM pin for support 16+ far field microphones making Alta a premier audio visual core board.

I appreciate the (pre)announcement and am looking forward to the Cottonwood SBCs.

From the libretech performance test results, it looks like the performance of the AML-A311D-CC is closer to (and perhaps better than) the ROC-RK3399-PC Renegade Elite, not the RK3328 Renegade.

I also think that you probably mean to use “It offers seamless hardware migration…” instead of “It offers seemly hardware migration…”.

Good luck!

ROC-RK3399-PC Renegade Elite and AML-A311D-CC Alta are two completely different platforms.

  1. The PC form factor was designed for high density with its low profile. The CC form factor was designed for compatibility with peripherals.
  2. RK3399 has many more IO and pinmux. It supports a multitude of camera, display, and other interfaces that A311D just does not have. So it’s really an apple to oranges comparison.
  3. We use Renegade Elite for our internal production line as it is geared more for high end commercial applications. Alta is more low end commercial and consumer applications.

This looks super promising. Pair it with a propsed camera, and offer a downliadable OS image that out of the box will do human detection with whatever model you think works best.

That kind of complete concept recipe is a powerful endorsement where people can assemble a known good functioning example.

Hi there, got an AML-A311D-CC Alta, I was wondering how to use PoE to power it, could someone help ?

You need a PoE mezzanine which communicates with the switch to enable power. The mezzanine is responsible for electro-isolation and downconverting the 48V DC down to to 5V AC. Mezzanines designed by our distributors will be available at the end of November.

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The AML-A311D-CC Alta and the AML-S905D3-CC Solitude are apparently available for preorder from LoveRPI: link

What is the recommended power supply size (Amps/Watts) for the new Cottonwood boards?

Without any USB peripherals or HATs:

Solitude needs 1A max.
Alta needs 2A max.

Is there an upper limit on the power supply size that these boards can make use of when peripherals are attached? For example, is there a benefit to selecting a 4A, 5A, or larger power supply? Or is there a maximum that these boards can draw through the USB-C connector that would make a larger power supply pointless?

I believe the Pi people have created some non-standard power delivery profile for their Raspberry Pi 5 that works with 5V @ 5A. When they detect a power supply that supports this profile, they allow additional power for the USB ports and HATs.

Knowing that Libre prefers to stick with standards as much as possible, I’m going to guess you didn’t do anything strange like that, but wanted to be certain.

From what I have read on the Power Delivery Standard, 3A (15W) is the highest standard power profile available for 5V. But, I also know there are a number of 5V/4A USB-C Power Supplies available on the market.

See the schematics. This board does not negotiate PD profiles for 5A but can use more than 3A if needed and if the power supply is willing to supply without negotiation. The USB ports are fused for 1A each so USB devices alone can use 4A backed by a 5A MOSFET.

You are going to get severe ohmic losses on your past 3A on most cables and components so it is unwise to design something like the Raspberry Pi 5 where you’re using 5A. If you compare the Raspberry Pi 5’s design to Alta’s design, you will see that Pi relies on PMIC where as Alta uses discrete components. Raspberry Pi traded simplicity for fundamental design problems as seen previously on the Raspberry Pi 3 low power issues.

Using discrete components for Alta is more complex and requires more care but you get benefits like better heat dissipation, more power, better impedance matching, and faster circuit response. Alta is able to handle high power devices much better than Raspberry Pi 5 simply because it doesn’t have 5V5A going through a tiny component, much like Le Potato handles high power devices much better than Raspberry Pi 3 with the same power supply.

There are advanced PMICs that together with selective discrete components can offer the best overall design in terms of cost and performance but you’re looking at more advanced and power hungry solutions in the hundreds of dollars. For a low power and low cost SBC, use a PMIC if your power supply is 12V. Avoid it like hell if your power supply is 5V and you need > 3A like on the Raspberry Pi boards since Pi 3. It is just bad news.


Are the usb fuses regular fuses or are they reset on power toggle? i forget what those fuses are called.

You can check the part number on the schematic for the datasheet.

Are you suggesting that the attached image is sufficient to explain what kind of fuses are being used? I’m just going to assume that the worst case scenario fuses are being used, or simply, the usb port is basically permanently unusable if any device exceeds 1a. FUSE-0805 means nothing, 0805 is the chip size, not a part number. 6F1 is also not seen anywhere else on the schematic, and a parts list is not provided that correlates with these 6XX identifiers. I think I’ll look elsewhere for my project since the response from the official team is basically google it.

USB ports fuses are standard self-resetable fuse. We use the same ones on various boards with different trip points. In this case, it is a standard 1A fuse that can come from a few manufacturers.

Hi, any news on the PoE mezzanine ?

The design has been completed by our affiliate. It’s awaiting manufacturing after CNY.

Does this mean that even though the pin-out of the Alta appears to mirror the pin-out of RPF 3B+ that the PoE boards compatible with RPF 3B+ should not be used with the Alta board?

We have not tested with the Pi 3 B+ HAT but the UART headers should conflict with it. Our partners are designing a 25W HAT for Alta.

In the meantime I have a board advertised to support PoE, but no way to use PoE! I guess I’ll sacrifice a $40 Solitude board to testing myself. I’m specifically interested in whether a Uctronics UC-775 will work as I plan to rack-mount a few of the boards. The stock heat-sink will need to go as its too tall, but shouldn’t be an issue replacing a lower profile heat-sink as the PoE board has a fan.