MIDI input latency over 300ms.

• Dec 31, 2018 - 01:51
Reported version
S3 - Major

I just upgraded to 3.0, and MIDI input is now painfully slow. When I press a key on the keyboard, there's a delay of almost a second before I hear the note sound. Then I release the key, and there's a similar delay before it stops playing. Worse, there's a separate delay for every note: if I play a chord, they don't all sound together. They get played arpeggiated, with a significant delay between notes.

This is in version running on macOS 10.13.4, using CoreMIDI for MIDI input.


That might be the case. It's 60 measures of full orchestral score, so not huge, but not tiny either. I tried an empty score with only one instrument, and there was no perceptible delay. Note, though, that it happens even when I'm not in note entry mode, so all it's doing is playing sound, not actually editing anything.

In reply to by peastman

With 60 measures in a score with >50 instruments, using the mouse and qwerty keyboard is fast, though it is very slightly slower than on the same score with 20 measures. I don't have a real noticeable slowdown until i get somewhere over 100 measures, and have a several year old computer with not much memory. It sounds like you have a midi issue. What's strange is that you're the only person I've see talking about midi being slower.

Title MIDI input very slow MIDI input slower than expected

I have compared midi input into an empty document. Musescore 3 shows a bigger delay than Finale Notepad 2012, chord shows a slight arpeggio. My system: Musescore Intel Core i7-7500U, 16 GB RAM, Win x64 10.0.18363.720, USB-Midi-Keyboard Akai LPK25.

Title MIDI input slower than expected MIDI input latency over 300ms.
Frequency Many Few
Status duplicate active
Reported version 3.0 3.6

Version 3.6.2 stable.
MIDI Input with both a USB MIDI Controller, and a USB MIDI Synthesizer both have incredible latency.
Compared with different APIs: ASIO vs best latency from WASAPI,MME,DirectSound, etc
MuseScore 3.6.2: 177ms w static, 352ms
Finale Notepad 2012: 24ms, 87ms
Ableton Live: 12ms, 97ms
FL Studio: 14ms, 97ms
The issue may actually be caused by the issue tracked below.

The Input latency has been an issue since 2016 from the forums.
The latency here makes it impossible to use midi input for anything faster than 100 bpm, as we can put in 3 notes a second before musescore fills out all the rests with notes, merges notes together as chords, etc.

Frequency Few Many
Severity S3 - Major S2 - Critical

Tested with five different MIDI controller keyboards, all have extreme latency ~ 300ms. Happens with any midi input at all. This basically prevents an entire feature from working.