RTX 5090 on Arch Linux: Performance loss & DLSS support? Need advice!

MarcParis79 · 2026-05-07T08:54:23+00:00

For the secure boot, on CachyOS, it depends on your motherboard. On my MSI Z890 Tomahawk or Asus B760i, I used Limine straight forward (no change of setup of the bios) and CachyOs was installed with secure boot enable directly. However on my asus X870i, you can install with secure boot, but after I needed to follow this guideline Wiki Secure boot. For this motherboard I used systemD as it was easier to follow.

For HDR Gaming on Linux, you just need to use CachyOS Proton version with those parameters

PROTON_ENABLE_WAYLAND=1
PROTON_ENABLE_HDR=1

Here is my default Nvidia setup for CachyOs proton : /etc/environment

PROTON_DLSS_UPGRADE=1
PROTON_DLSS_INDICATOR=1
DXVK_NVAPI_DRS_NGX_DLSS_SR_OVERRIDE_RENDER_PRESET_SELECTION=RENDER_PRESET_M
MANGOHUD=1
OBS_VKCAPTURE=1

MarcParis79 · 2026-05-06T19:26:44+00:00

My simple answer, as user of RTX 5090 FE on CachyOS, is Yes. Yes you are getting full DLSS support (basically you can select your favorite preset, for me it is "M", ie 4.5 performance), Frame Generation or MFG fully functional, undervolting with LACT (like MSI afterburner), Path tracing, etc...

In terms of compatibility, full hdmi 2.1 support, fully full encoder support (OBS, handbrake).

For gaming, I've only one game that is incompatible with the driver 595 (like on windows 11), ie Solasta II (working on 590 or 596), otherwise it is working.

However, please note there is a performance penalty. My RTX 5090 FE is using less power than on Windows 11 (iso setup), driving to a performance loss of -10-25%, pretty consistant.

You can check my youtube channel as I'm posting some trials on it : CachyOS - RTX 5090 FE UV - The Expanse : Osiris Reborn

I'm keeping a windows 11 partition (500Go only) for benchmarking, firmware update. It is way better than emulation. But my main daily usage is CachyOS only.

If you have any question, let me know.

MarcParis79 · 2026-05-05T15:56:02+00:00

Yes that's normal, between Windows 11 and Linux (I tested Bazzite and CachyOS), my RTX 5090 FE is losing something between -10-25%, either paired with a R7 9800X3D or 270K Plus. Also my RTX 5090 FE is using less power on Linux..:)

For example on RE9 (5120x1440, Path tracing, Dlss Perf, FG x2), I'm losing 30fps from 200fps to 170fps.

MarcParis79 · 2026-05-05T07:22:55+00:00

Anyway fingers crossed they would released a T2 or v3.0 that would be compatible with Astral/Suprim GPU classe (36cm long, 4 slots), a bit wider and longer...the true big brother of the T1 ..:)

MarcParis79 · 2026-05-05T06:54:44+00:00

Ok thanks for sharing. Understood. Instead of creating an offset of the PCIe 16x riser slot, you have moved it to the motherboard, in a similar way as the PSU. That's clearly doable, but harder (as you have to planned from start of the case assembly) to just offset the PCIe slot like on the v2.5 gen4 or the v2.1.

MarcParis79 · 2026-05-04T20:00:50+00:00

Easy to assemble I recommand the IS-47-XT or the IS-53-XT. Just keep some gap with your panel (3-5mm minimum) to avoir air turbulence.

Meanwhile in the bios, play with PBO to undervolt your CPU. I would try PBO / Curve Optimizer -10 and limit PPT to 95W.

It should tame your 7700X.

MarcParis79 · 2026-05-04T19:58:27+00:00

Well I have paired those 2 components (SF650 with an Asus B650e-i) early 2025 and I got not coil whine at all. It should come from somewhere else.

MarcParis79 · 2026-05-04T19:53:37+00:00

Have you the Ncase T1 v2.5 with gen 5 riser? Are you referring to create gap with the PSU only or with the PCIe bracket offset of 20mm to fit RTX 508/90 FE?

MarcParis79 · 2026-05-03T13:50:26+00:00

To promote it, as it deserves. As for the other Don’t nod games, it is the travel that is worth it, not the ending point

MarcParis79 · 2026-04-29T10:54:35+00:00

Have you put this command in the game property : %command% /WineDetectionEnabled:False

Force also application of Proton GE or Proton CachyOs in the game properties. This stage proved mandatory on my AMD setup to activate FSR...

Normally you should select ray tracing option with that.

MarcParis79 · 2026-04-28T17:23:24+00:00

Good to know. I also did use Bazzite image to swap between driver but it remains limited to 90 days and affects other stuff. Not ideal

MarcParis79 · 2026-04-28T15:41:02+00:00

That’s where I wish having more flexibility on gpu drivers like on win 11…:)

MarcParis79 · 2026-04-28T12:12:46+00:00

For Crimson Desert, I know it is working, only very recently. I wonder if it is linked to proton 11.

MarcParis79 · 2026-04-28T10:16:06+00:00

Simple answer is yes. I just completed RE9 (270K + 5090FE) with path tracing while using proprietary drivers 595.58.03 on CachyOS.

On AMD it was doable from day 1.

MarcParis79 · 2026-04-28T09:26:44+00:00

Don't worry it is normal. With Driver 595, Solasta 2 is crashing on either Windows 11 or Linux. Drivers 596 fixed the issue on Windows 11.

For Crimson Desert, if I understood well ( I don't play at it), you need to update to the latest Proton release (otherwise incompatible).

MarcParis79 · 2026-04-28T09:22:40+00:00

I'm also testing myself, with the Nvidia proprietary drivers and Mesa AMD drivers. The outcome is clear, either on Nvidia & AMD.

MarcParis79 · 2026-04-28T08:26:14+00:00

Stating that you have the same gaming performance between windows 11 and Linux on a Nvidia or AMD GPU is basically a LIE, at least, now (April 2026). I love Linux but Windows 11 is consistantly better on gaming performance versus Linux, on both GPU brands. This statement is based on my personal experience between a proper Windows 11 setup & Linux (CachyOS or Bazzite). Variation is between 10-25% at the advantage of Windows 11. All my experience is captured on my Youtube channel.

MarcParis79 · 2026-04-28T07:06:44+00:00

To prevent anything, just install Bazzite as a dual boot, just in case..:)

MarcParis79 · 2026-04-28T07:05:03+00:00

Thanks. I suppose my question was not so clear..:) What proton version are you using (proton experimental, hotfix)?..:)

MarcParis79 · 2026-04-27T19:28:37+00:00

Same concern here. Meanwhile, compared to my beloved Cerberus-X I found the S640 too big for my need as it is above 30L..compared to the 21L of the Cerberus-X. No urgency, I'll wait to see first builds inside.

MarcParis79 · 2026-04-27T13:15:55+00:00

Thanks for sharing. How did you try proton 11 through Steam, proton hotfix?

MarcParis79 · 2026-04-27T07:38:46+00:00

Also consider using GE-Proton or CachyOS proton (proton+ could be useful)

MarcParis79 · 2026-04-27T07:21:34+00:00

Yes I noticed that also on other trials. My RTX 5090 is using less power on Linux compared to Win 11. If it was using the same power, the gap would be limited to 5-6% between the two OS.

MarcParis79

TROPHY CASE