Arch Linux

LunarLambda

Member

Registered: 2021-08-02

Posts: 9

[Solved] Nvidia GPU - Enable DisplayPort output during early boot?

I recently upgraded my monitor to a Samsung S27DG50. It has one issue:

My motherboard (Gigabyte Z370 HD3) doesn't seem to be able to use the DisplayPort output of my GPU (Nvidia GTX 1070) at all.
I get a black screen, and this continues into Linux (I have to unlock my encrypted disk blindly) until GDM starts at which point the display comes up and works perfectly fine.

If I plug the monitor into the HDMI output of the GPU, it works fine. However, this then means I'm limited to a maximum refresh rate of 144 Hz instead of the maximum of 180 Hz I can get over DP.

Because I think this is a motherboard firmware issue (and I'm not likely to get updates for it anymore), I'm wondering if I can somehow 'nudge' the GPU to activate the DP output in early userspace instead.
I've never really encountered this kind of compatibility issue before, so I'm not really sure what my options are. My PC is fairly old and buying a new motherboard/cpu/etc. is not really an option right now (yet), but I'd still like to get the full performance of my new monitor at least.
I don't really wanna deal with having to switch inputs back and forth every boot. I'm fine with not being able to see the UEFI stuff unless I'm on HDMI, but it would be nice to see my boot logs and disk decryption prompt at least.

Some assorted info about my HW:

CPU: Intel i3 8100
GPU: Nvidia GTX 1070
Motherboard: Gigabyte Z370 HD3
Monitor: Samsung S27DG50 (2560x1440 @ 180 Hz)
Linux Kernel: 6.11.6.arch1-1
Nvidia: 565.57.01-2
mkinitcpio: HOOKS=(systemd autodetect microcode modconf kms keyboard sd-vconsole sd-encrypt block filesystems fsck), otherwise unmodified

I would be happy to provide any other information of any kind.

Last edited by LunarLambda (2024-11-10 15:25:55)

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 12,926

Re: [Solved] Nvidia GPU - Enable DisplayPort output during early boot?

The latest firmware for your motherboard appears to be F14 from 9 nov 2021 . Are you using that version ?

I found the Motherboard Manual .
It's for HW revision 1.0 , verify if that's your board (see pictue on page 2 of manual ) .

Goto 2-5 Peripherals > initial display output (page 31 )
Change the setting from IGFX to the slot your nvidia card is in (likely PCIe1 slot, marked as PCIEX16 on the MB.)

Test if this does what you want.

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

LunarLambda

Member

Registered: 2021-08-02

Posts: 9

Re: [Solved] Nvidia GPU - Enable DisplayPort output during early boot?

It's already set to PCIe1. And yes the firmware is on the latest version. I can double check the motherboard markings but I'm pretty confident everything is configured correctly. Like I said, HDMI output on the GPU works, but not DP.

cryptearth

Member

Registered: 2024-02-03

Posts: 962

Re: [Solved] Nvidia GPU - Enable DisplayPort output during early boot?

have you plugged anything into the motherboard video outputs? if so: don't! if you want to use your dGPU only plug into it

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 12,926

Re: [Solved] Nvidia GPU - Enable DisplayPort output during early boot?

If the system is set to use the nvidia card as primary, it should enable all attached outputs, atleast in vga mode.

One thing that may help somewhat is to ensure linux does initialise the nvidia card early .

remove kms from the mkinitcpio hooks (kms hook only matters for in-kernel graphic drivers)
Add nvidia_drm.modeset=1 to your kernel parameters.
That will prevent linux from trying to use the simpledrm device AND set the nvidia card to the correct mode .
(latest nvidia driver is not supposed to need that anymore, but we want to be sure).

Also enable early kms loading .

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

LunarLambda

Member

Registered: 2021-08-02

Posts: 9

Re: [Solved] Nvidia GPU - Enable DisplayPort output during early boot?

That did it, thanks! It does take a bit to show up but it works!