GeForce RTX 5070 Ti on Linux (Debian 13)

I got a GeForce RTX 5070 Ti GPU for Christmas. I want to do some AI stuff with it. Maybe I’ll have something about that to post soon. But getting it to work on my system was really a chore! I’m running Debian 13 with a ROG STRIX B550-F motherboard (not the wifi version).

After I put it in and tried to boot, I saw Grub’s selection screen, but almost immediately my monitor went black, and within 10 or 20 seconds it lost its connection entirely.

By adding an extra echo line after initrb in grub I could see that at least that part was running. But it was dying soon after, and I had no messages to diagnose the problem. Doing something like journalctl -b -1 gave nothing (or rather info from the boot prior).

Adding modeset stuff to grub didn’t help. Adding noacpi or pci=noacpi didn’t help. Turning off ACPI altogether with acpi=off let me boot though. I didn’t have working graphics, but I could Ctrl-Alt-F3 to a console and run commands.

Even after installing nVidia’s driver, I didn’t have a working display. I followed their instructions for the open-source driver, which gave me version 590.48.01. (Their old closed-source driver doesn’t support newer cards like the 5070 Ti.) This reddit thread helped too. Basically I did this:

apt-get install linux-headers-amd64
apt-get install linux-headers-$(uname -r)
wget https://developer.download.nvidia.com/compute/cuda/repos/debian13/x86_64/cuda-keyring_1.1-1_all.deb
dpkg -i cuda-keyring_1.1-1_all.deb
apt-get update
apt-get install nvidia-open

Then I could run nvidia-smi, and lsmod | awk 'NR==1||/nvid/' showed nvidia_uvm, nvidia, and drm. Also I could see from mokutil --sb-state that I was running with SecureBoot disabled, which Google AI thinks is a good idea.

But my display problems continued. When I ran startx by hand I could see a segfault in /var/log/Xorg.0.log. Later I got this to go away (perhaps it was adding grub commands to blacklist nouveau sooner?), and then X would start, and with pstree I could see that xfce was running and even restoring commands from my session, like terminals and firefox. But the display wouldn’t switch: I was still looking at the console, with some messages printed by X.

In the boot log I saw errors about not finding the DRM device, and before that there were messages about IRQ problems for the PCI device. There was a recommendation to use pci=biosirq, but that didn’t help. (I think that hint is for really old systems anyway.) I figured probably acpi=off was messing things up.

I tried upgrading my motherboard BIOS. It was a few years out-of-date. I installed the latest version (3635, published 2025-11-06 with build date 2025-09-30). After unzipping, I renamed the file to RSB550FG.CAP. Then I formatted an 8GB USB drive with mkfs.vfat --mbr=yes -I -F 32 /dev/disk/by-id/usb-SanDisk_Cruzer_Fit_4C532000030816101033-0\:0. Then I copied the file to the root of the drive, ran sync, and yanked the USB stick. With case power on but the computer off, I stuck the USB into the Flash BIOS port in the back and held down the Flash BIOS button for a few seconds. When I let go, the USB activity light started blinking. If I shaded the motherboard panel I could see that the Flash BIOS light was blinking too. So I let it run for 5 or 10 minutes, and when I checked the blinking had stopped. I booted, and the BIOS still worked!

Somehow this made grub much slower. Every keystroke took a second or two to register, and I easily lost letters. I tried some BIOS tweaks, like turning off Legacy USB support. But the only thing that worked was changing GRUB_GFXMODE to 1024x768. Actually 640x480 was even better, but all the lines wrapped and it was unreadable. I’m pretty sure a lower resolution shouldn’t be needed. I think flashing the BIOS wiped all my old settings, so maybe there is some better way to restore grub’s performance, but I haven’t found it yet.

Anyway, the BIOS upgrade didn’t solve my problems. Allowing ACPI still caused a failure right after starting the kernel. I suspected that a proper fix to acpi=off would do the trick. I found this article about using the 5070 Ti on Linux, and I started changing BIOS settings. The issue turned out to be “Above 4G Encoding” (under “Advanced > PCI Subsystem Settings”). For me it was disabled. When I enabled it, suddenly everything worked.

That’s it. I haven’t tried installing cuda-toolkit yet, but that’s next. I’ve had an AMD card for years. A year or two ago I got ROCm compiled, after much struggle, but pytorch would just segfault. I’m excited to play around with AI a bit now.

Anyway, “Above 4G Encoding” was definitely not in Google AI’s many, many recommendations as I searched for solutions, so perhaps this blog entry will go into its next training and help someone out.

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