Making an NVIDIA eGPU Actually Work on Linux (The Hard Way)

Fri, 27 Mar 2026 00:00:00 +0000

I have a Framework Laptop 13 (Intel 13th gen) and an RTX 3070 sitting in a Thunderbolt 3 eGPU enclosure. On Windows it just works. On Linux, I got this:

NVRM: This PCI I/O region assigned to your NVIDIA device is invalid:
NVRM: BAR1 is 0M @ 0x0 (PCI:0000:04:00.0)

The GPU was right there on the PCI bus. The driver loaded. And then it gave up because BAR1 — the 256MB framebuffer aperture the GPU needs to function — had zero bytes allocated. A 220W GPU reduced to a very expensive space heater.

I spent the better part of a weekend on this. Here is what I found.

Thunderbolt on Andrea Cervesato

Making an NVIDIA eGPU Actually Work on Linux (The Hard Way)