Factorio Forums

Sometimes when the game changes music to a space age specific track the game will lag briefly. I collected frame time data for about 1 minute on each surface while changing the music every couple of seconds. Every surface except nauvis has high frame time spikes.

I forced the game to change music using the "Play the next music track" hotkey in controls but the lag spikes happen even when the game changes the music normally. The lag spikes also occur on a different computer with different hardware and os.

Thanks for the report.
The issue was related to variable music tracks and their threads. The threads could be sleeping when the track was ordered to stop, the game would wait for those threads which could lead to a noticeable stutter.

Similar stutter could occur if you press "Play next" while a variable track is generating and loading longer sample(s).

While looking into this I've also noticed a bug with Vulcanus 9 intermezzo and intermezzos in general.

All of these issues are fixed for the next release, 2.0.43.