Tried Nvidia's GTX 1080 - still no external GPU on a Pi

Earlier today I did a livestream on my YouTube channel to attempt using an Nvidia GeForce GTX 1080 on a Raspberry Pi Compute Module 4.

As with all my testing, I'm documenting everything I learn in this GitHub issue, which is part of the Raspberry Pi PCI Express Card Database website.

It's only been a few hours, but I've already gotten good suggestions for better debugging than I was able to do on the stream. And someone pointed out it might be the case, due to 32-bit memory limitations on the BCM2711's PCIe bus, that no GPU with more than 4 GB of onboard RAM could work. Though it's hard to confirm there'd be no software workaround—even 1 and 2 GB graphics cards (AMD and Nvidia) are crashing the kernel in similar ways.

The full livestream is available on replay and is embedded below:

And in that livestream, I compared the 'chonky' size of the 1080 card to the diminutive ASRock Rack M2_VGA card I tested a few weeks ago, tried installing Nvidia's proprietary driver on 64-bit Pi OS (which locked up), tried recompiling the kernel with Nouveau (which locked up), and then documented all the failures in the GitHub issue linked earlier in this post.

I was expecting failure, and said as much at the beginning of the stream—5% chance of success, 10% chance of releasing the magic smoke—but it would be nice to get any graphics card to work well on a Pi, for a variety of uses. But probably not AAA gaming, since gaming on Linux is a tough proposition even in the best of circumstances.

Some people also suggested testing on an Nvidia Jetson board, or a Honeycomb, but the former is a bit pricey, and the latter seems to be unobtanium right now (as with so many components these days). I mean heck, I would also love to find a way to loan an Ampere server for a short time so I could basically use the best ARM hardware on offer... but alas those prices are astronomically beyond my budget right now :)

I'll keep plugging away, and hopefully if not me, then someone will get an AMD or Nvidia GPU working on the Pi. Coreforge is certainly close with an old Radeon 6450.