Audio latency is often the largest contributor to overall latency in osu! For Windows users, this latency typically includes 18ms from the system, plus keyboard input latency (the time it takes to hear the hitsound after clicking) and sound processing latency (which depends on your audio hardware).
Using a keyboard with low input latency can help on any operating system. You can check the latency of popular keyboards on https://rtings.com.
With this setup, I reduced my audio latency to just 12ms (from click to hitsound) instead of 40ms with my old mechanical keyboard and REAL on Windows 11.
Osu!lazer have a hidden -18ms offset by default as Windows is the most popular OS for osu, so comfortable global offset in my case is +6ms. Play a few games on different ranked maps (don't use stream maps) and try to listen your keyboard instead of hitsounds. You will see a recommended offset in Global Offset settings.
Keyboard:
Using a keyboard with low input latency can help on any operating system. You can check the latency of popular keyboards on https://rtings.com.
For Windows 10/11:
- Use REAL: A program that can reduce audio latency for certain audio devices. You can find it here: [https://github.com/miniant-git/REAL]. This software works with the current default audio output device and reduces the sampling buffer from the default 480 samples (10ms) to 128 samples (2.67ms).
- Download and use Hidsubf Driver: Download it from [https://github.com/LordOfMice/hidusbf] to overclock your keyboard and even your tablet (it’s best not to set the tablet above 500Hz). You will need to click "Install Service" and reboot your device occasionally. This driver may not work consistently after sleep mode, as Windows 11 tends to remove it quickly because it lacks a certificate. Your devices will function on the Hidsubf driver for some time even after switching back to the default Windows driver—at least until the next device reboot or reconnection.
If You Want Minimal Audio Latency:
- Install Ubuntu (Linux): Consider setting up Ubuntu as a second operating system if you have a free space on a local drive (it's unfortunate if you have only C drive as you need special utilities to safely divide your memory).
- Get a Good Sound Card: Look for a sound card with low audio latency or check if your GPU can perform well as a sound card. Surprisingly, my old GTX 750 Ti performs better in sound processing than my current GTX 970 (about a 7ms difference). I reconfigured sound processing to use the second GPU (750 Ti) by editing /etc/asound.conf (create this file if it doesn't exist):
defaults.pcm.card 2 # Processing card ID
defaults.ctl.card 1 # Output connected to your headphones
You can check your card IDs by using the command in the terminal: aplay -l
You should to reboot your system after saving the file (ALSA reboot doesn't work for this parameters).
Result:
With this setup, I reduced my audio latency to just 12ms (from click to hitsound) instead of 40ms with my old mechanical keyboard and REAL on Windows 11.
Osu!lazer have a hidden -18ms offset by default as Windows is the most popular OS for osu, so comfortable global offset in my case is +6ms. Play a few games on different ranked maps (don't use stream maps) and try to listen your keyboard instead of hitsounds. You will see a recommended offset in Global Offset settings.