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RandomRanger

Member

Registered: 2023-06-26

Posts: 42

eGPU FPS Lower than iGPU in certain games

This is a re-post of a thread I have on the Framework forums
https://community.frame.work/t/egpu-fps … ames/58243

Hardware: Framework 16 with Ryzen 7 7840HS | RTX 3080ti via Razer Core X
Software: Plasma + Zen Kernel, nvidia dkms drivers

One thing I’ve noticed is that in some games, Baldur’s Gate 3 and Space Marine 2 specifically, the framerate seen by the user will be significantly lower than what it would be if I had played on just the iGPU. In these cases, the CPU is not hitting 100% on either single/multicore and the GPU reports a respectable utilization (90%+ with power draw close to max). Despite these metrics however, the framerate will be seemingly capped at 30fps, when the significantly weaker iGPU is capable of higher framerates. I do not see this issue in any other game I've tested (i.e. the system behaves exactly as expected) but I do not know what they could have in common.

I tested Baldurs Gate 3 last night with a fresh install of Fedora 40 and it did not have this issue, so it suggests to me that it's likely a software issue. I don't know if it's related, but the entire Plasma interface will also occasionally freeze entirely while gaming.

Anyone have some troubleshooting ideas to narrow down what it could be?

Last edited by RandomRanger (2024-09-27 17:51:20)

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Any sufficiently advanced magic is indistinguishable from science.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 23,430

Re: eGPU FPS Lower than iGPU in certain games

Are you sure the nvidia GPU is actually used? Afaik Baldurs Gate 3 has a native vulkan renderer and as such the way it selects the to be used vulkan driver might not be entirely transparent, to be entirely sure it picks the correct one you should install mesa-vulkan-layers and pass the appropriate variation of MESA_VK_DEVICE_SELECT= (according to google the vid:pid for a 3080Ti should be 10DE:2204 so MESA_VK_DEVICE_SELECT=10DE:2204! ) see https://wiki.archlinux.org/title/Vulkan … en_devices

If that isn't it symptoms also sound like you might be double vsyncing. If you're on Xorg make sure to suspend the compositor (Ctrl+Shift+F12 by default) and/or disable vsync in game.

RandomRanger

Member

Registered: 2023-06-26

Posts: 42

Re: eGPU FPS Lower than iGPU in certain games

I validated the correct GPU was in use using mangohud for Baldurs Gate 3 and nvtop for Space Marine 2 (given that overlays prevent the game from launching). I also tested with the eGPU disconnected, and the performance was significantly increased (e.g. more than double).

Regarding double vsync, I am running on wayland, but there's no harm in checking vsync options anyways so I'll give that a shot.

Last edited by RandomRanger (2024-09-27 19:47:31)

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Any sufficiently advanced magic is indistinguishable from science.