Chestnut combines a USB-to-PCIe board with custom open firmware. Its unusual feature is that GPU compute and ordinary USB4 docking do not have to follow the same software path.
What changed since launch
The launch post introduced the board at $249 and a complete RX 9060 8GB kit at $799. On September 8, the store still lists the dock at $249 but the ready-to-drive kit at $899, with a four-to-twelve-week shipping estimate. The bare dock requires your own GPU and power supply.
These are different configurations. Comparing only the smallest price with a complete system would omit essential hardware. Availability and delivery estimates should be checked again before ordering.
USB4 and USB3 are not interchangeable promises
The store describes ordinary USB4 dock use with a PC. For USB3 or USB2 GPU access, it instead points to tinygrad. The firmware repository documents custom communication commands. This is a software-specific compute route, not a promise that every graphics application will recognize an external GPU on any USB port.
The TinyGPU macOS guide specifies macOS 13 or later, USB4/Thunderbolt and supported AMD RDNA3-or-newer or NVIDIA Ampere-or-newer hardware, with a driver extension and compiler setup. That guide’s requirements should not be replaced with the broader phrase “works on Mac.”
Check the whole connection chain
Consider two fictional uses of the same board. One person wants an existing graphics application to render through an external card. Another wants a tinygrad workload to run over the custom compute path. Success in the second case does not prove support for the first application, its display output or its driver.
Identify the host port, cable, board firmware, GPU, software backend and workload before treating compatibility as established. The cover draws the two paths separately so the USB connector does not hide their different requirements.
The board also targets Comma’s driving hardware, but this article does not test a vehicle installation or establish driving-system safety. Our explanation concerns the hardware and software boundary. No GPU benchmark or universal application-compatibility claim is implied.
Update launch versus current kit pricing; distinguish USB4 dock, USB3 tinygrad access and supported macOS compute from universal eGPU support.