NVIDIA engineer Kamil Łysik measured how fast Linux desktops react to a key press and found no clear winner between Wayland and the older X.Org server. He presented the results on September 30, 2026, at XDC 2026, the X.Org Developer's Conference in Toronto. The tests also show that XWayland no longer adds an extra frame of delay, Hardware Busters reports. That undercuts a long-running reason some Linux users and game developers gave for staying on X.Org.
Wayland, X.Org and why latency matters
A Linux desktop needs a display server, the software that takes input and puts windows on the screen. X.Org, also called X11, did that job for decades. Wayland is its replacement, and on Wayland the compositor itself does the work. The compositor is the program that draws every window into the final picture, such as KWin on KDE Plasma or Mutter on GNOME.
Latency here means the time from pressing a key to seeing the screen change. Gamers, artists and anyone typing fast feel extra delay even when they cannot name it. XWayland is the compatibility layer that lets older X11 programs run on a Wayland desktop.
How NVIDIA measured it
Łysik built an automated rig rather than relying on software timers. A microcontroller, an ESP32 or a Raspberry Pi Pico, pretended to be a USB keyboard and sent key presses. A photodiode, a fast light sensor, watched the monitor and recorded when the screen changed. Hardware Busters says a photoresistor was tried first and rejected, because it took more than 10 ms to respond.
His talk abstract on the XDC 2026 schedule says the aim was "a fairer basis for discussing latency." It compared several compositors, window managers and display setups.
| Part of the test setup | Version or model |
|---|---|
| Graphics card | NVIDIA GeForce RTX 5070 |
| Driver | NVIDIA 610.57.04 |
| Monitor | LG 27GN950 at 144 Hz |
| Linux kernel | 7.1.7 |
| KDE compositor | KWin 6.7.4 |
| GNOME compositor | Mutter 49.7 |
| X server | X.Org Server 1.21.1.24 |
What the results show
Wayland and X.Org delivered close latency with no consistent winner, Hardware Busters reports. That is a change from earlier independent testing. A January 2025 test found 6.5 ms more cursor delay on Wayland than on X11. At 144 Hz, one frame lasts about 7 ms, so that gap was close to a full frame.
XWayland improved too. It used to add an extra frame of delay. In NVIDIA's tests, that extra frame is gone.
The biggest effect came from variable refresh rate (VRR). With VRR, the monitor waits for each new frame instead of refreshing on a fixed clock. Turning it on "drastically" improved responsiveness on both display servers and removed any measurable difference between them. Hardware Busters sums it up: "switch on VRR, and stop worrying about which session you picked."
NVIDIA's other XDC project: Display Config Server
NVIDIA also brought new code to the conference. On September 28, engineer Austin Shafer presented Display Config Server. The schedule calls it "a new open source solution to display wall configuration and persistence." Display walls are large screens made of many monitors, used in places like TV studios.
It builds on Vulkan's direct-to-display support, which lets a program drive a screen without a desktop in between. The schedule presents it as an alternative to the X-based way display walls are set up today.
What this means for developers
If you avoided Wayland because of input lag, test again. On current NVIDIA hardware and drivers, these results suggest the session type no longer decides latency. Your monitor settings matter more.
Turn on VRR first. It made the largest difference in NVIDIA's tests, on both Wayland and X.Org. Check that your compositor, driver and monitor all support it, and that it is actually active.
Game and app developers can worry less about XWayland. A game still built for X11 should no longer pay an extra frame when it runs on a Wayland desktop. Native Wayland support is still worth planning, but not because of this delay.
Keep the test's limits in mind. It used one NVIDIA card, one 144 Hz monitor and older compositors than the newest releases. GNOME 51 reworked frame scheduling in Mutter in September, and KDE Plasma 6.8 brings more Wayland fixes. Results on other GPUs, or on those newer versions, may differ.
If you care about latency, measure it yourself. A cheap microcontroller and a photodiode are enough to repeat NVIDIA's method on your own hardware.
This article was first published on Tech AI Wire.
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Related on Tech AI Wire
- GNOME 51 ships reworked frame scheduling in Mutter
- KDE Plasma 6.8 beta brings Kup backups and Wayland fixes
Sources
- NVIDIA Puts Wayland vs X.Org Latency to a Photodiode Test, and Neither Side Wins - Hardware Busters
- XDC 2026 - X.Org Developer's Conference (28-30 September 2026) timetable - freedesktop.org Indico
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