Maker Aiden Chostner has designed a PCI Express graphics card that you can build yourself — though expectations as to its performance must be tempered by the understanding that it’s powered by a Raspberry Pi Pico 2 W microcontroller board, albeit one that’s been heavily overclocked.
"Recently, I began exploring circuit design, and I liked the idea of creating my own custom graphics card because it sounded like a fun project," Chostner explains. "After some back and forth of choosing requirements for the GPU, I settled on using a Raspberry Pi Pico [2 W] as the main processor. It already had a graphics library made for it, which would make adding HDMI support simple. I saw PicoDVI by Luke Wren, but I wanted to add more RAM and some extra capabilities."
Don’t let that chunky "su…
Maker Aiden Chostner has designed a PCI Express graphics card that you can build yourself — though expectations as to its performance must be tempered by the understanding that it’s powered by a Raspberry Pi Pico 2 W microcontroller board, albeit one that’s been heavily overclocked.
"Recently, I began exploring circuit design, and I liked the idea of creating my own custom graphics card because it sounded like a fun project," Chostner explains. "After some back and forth of choosing requirements for the GPU, I settled on using a Raspberry Pi Pico [2 W] as the main processor. It already had a graphics library made for it, which would make adding HDMI support simple. I saw PicoDVI by Luke Wren, but I wanted to add more RAM and some extra capabilities."
Don’t let that chunky "sub-zero" cooler fool you: the heart of this graphics card is a Raspberry Pi Pico 2 W. (📷: Aiden Chostner)
Traditionally, these types of add-in board was used to provide a video output for a desktop or desktop-class computer — starting with text-only and monochrome graphics for early models before adding color, acceleration for 2D and later 3D drawing operations, and video decoding capabilities. What Chostner has built is in the form of a PCI Express add-in board, but it’s technically an entirely standalone computer system to the point where it can even make use of the Raspberry Pi Pico 2 W’s integrated Wi-Fi radio to pull down remote data and render it on the HDMI and VGA video outputs. In fact, you don’t even need to put the PCI Express connector into a PCIe slot: just provide power and that’s enough.
While the Raspberry Pi Pico 2 W’s 520kB of static RAM (SRAM) is more generous than that provided on its predecessor, it’s still not much by graphical standards. "I added 32MB of VRAM (Video Random Access Memory), which is about 250 times less capacity and 36 million times slower than the memory on a modern GPU," Chostner says of the board’s final specifications. "As you can probably tell, I was not going for speed."
While designed as a PCIe add-in board, the Pico2DVI is an entirely standalone device requiring only power and a display. (📷: Aiden Chostner)
While it can’t act as a 3D accelerator for your desktop, it can still output graphics: Chostner has written some sample applications that include a version of Conway’s Game of Life rendered on-card and has plans to have it run other, more intensive, applications including id Software’s classic first-person shooter Doom. In furtherance of that goal, the RP2350 microcontroller enjoys a hefty overclock — to the point where Chostner felt the need to add a Peltier-based "sub-zero cooler" with large heatsink and software-controlled fan.
The project is documented in full on Instructables, with design files and source code provided on GitHub under the permissive Creative Commons Zero public-domain license.