Large lag/stutter spikes when using external FPS limiter #34
Description
This may be an unavoidable issue caused by the game speed synchronisation logic, but posting this so the solution/cause for this issue is documented somewhere.
While playing BBS on my steam deck with the Luabackend was in place I was getting seemingly random bouts of large lag/stuttering spikes, even while no scripts were loaded.
The spikes of lag didn't seem to be related to how much was going on in the game at the time, with the spikes somtimes also happening in completly empty rooms when just moving the camera or opening/closing the menu.
The performance stats in the steam deck would continue to show the current FPS as 60 or 59 and not show any significant load during the spikes.
Based on the advice from this post I tried removing the BBS and 1.5+2.5 collection save data which didn't help: #1 (comment)
What ended up fixing the issue was removing/increasing the FPS limit set in the steam deck options itself (so not the in game FPS setting).
While the steam deck had a 60 FPS cap set for the game (matching the ingame setting) the stuttering would be present and happen at seemingly random times.
After increasing the limit in steam to 90 FPS while keeping the ingame FPS as 60 the lag spikes seem to have instantly gone away.
If I pay very close attention I think there are still tiny performance dips to 59 FPS, so I believe playing with the Luabackend in place with the 60 FPS limit set externally (such as through steam or nvidia control panel) was turning these tiny dips into large lag spikes.