From 12531fe42422e3ed0987bc825579780805efa2da Mon Sep 17 00:00:00 2001 From: hypevhs <4498312-hypevhs@users.noreply.gitlab.com> Date: Tue, 19 Aug 2025 14:31:23 -0500 Subject: [PATCH] Hardware: lower-latency ALSA headroom Co-authored-by: notfranko_ --- content/docs/hardware/_index.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/content/docs/hardware/_index.md b/content/docs/hardware/_index.md index 008dda3..455776b 100644 --- a/content/docs/hardware/_index.md +++ b/content/docs/hardware/_index.md @@ -26,7 +26,10 @@ title: VR Gear & GPUs **Notes:** - **Nvidia Wired VR Workaround**: Wired users should certainly set `XRT_COMPOSITOR_USE_PRESENT_WAIT` to 1 which changes the swapchain to explicit sync behavior and `U_PACING_COMP_TIME_FRACTION_PERCENT` to 90, representing 90% of the time it takes to render a frame can significantly reduce the latency effect with Nvidia GPUs. There are notable frametime issues in the driver still which may result in stutter but this should vastly improve the experience. - For Nvidia proprietary drivers *older* than 565, (please try to update!), the [vulkan-layers](https://gitlab.freedesktop.org/monado/utilities/vulkan-layers) must be installed in order to not crash: [*AUR*](https://aur.archlinux.org/packages/monado-vulkan-layers-git)・[*Fedora*](https://packages.fedoraproject.org/pkgs/monado-vulkan-layers/monado-vulkan-layers/) -- Audio over displayport is known to temporarily cut out when new audio sources spring up on pipewire [without a fix to add alsa headroom](https://wiki.archlinux.org/title/PipeWire#Audio_cutting_out_when_multiple_streams_start_playing) +- Audio over DisplayPort is known to temporarily cut out whenever new audio sources spring up on PipeWire [without a fix to add ALSA headroom](https://wiki.archlinux.org/title/PipeWire#Audio_cutting_out_when_multiple_streams_start_playing). + - This fix's default values adds a lot of audio latency to the entire system. If you're someone who is sensitive to audio latency, you can try changing period-size=64 and headroom=512. If audio continues to cut off, double these values. + - Also, this fix will change the latency of _all_ audio output devices. To tweak the audio output latency of your HMD _only_, which is usually sufficient to prevent cutouts, use `pactl list sinks` to identify the Sink Name that your HMD is currently connected to, and edit the headroom fix file by changing the `node.name`. + - For example: `node.name = "alsa_output.pci-0000_03_00.1.hdmi-stereo-extra2"` (not a typo, it's still connected via DisplayPort) ## XR Devices