Low update FPS when many notes are on screen in mania

[longnguyen2004]

Type

Performance

Bug description

I was playing a storyboard map, which has the SV multiplier set to 0.01x to prevent turning off the storyboard. However, there are huge lag throughout the map. So I turned off the storyboard to see if it persists, which it did, so it's not due to the storyboard.

Also, this is not related to SV changes during the map, but note density in general. You can take any maps, reduce the scroll speed to minimum, and it'd exhibit the same problem (screenshot below).

Screenshots or videos

Version

2023.924.1

Logs

probably not required

[peppy]

Please provide a link to the beatmap.

[longnguyen2004]

https://osu.ppy.sh/beatmapsets/1248233#mania/2594303 - loved map with 0.01x SV multiplier throughout (turn off storyboard to confirm it's not the storyboard)

But like I said, you can pick any maps, set scroll speed to 1, and the same perf degradation will occur.

[longnguyen2004]

Map: https://osu.ppy.sh/beatmapsets/533893#mania/1131026, scroll speed set to minimum to exaggerate the issue

Argon/Argon Pro

Triangles

Classic

R Skin v3.1

[peppy]

Surely you don't play at this scroll speed?

[longnguyen2004]

I don't play at this scroll speed yes, it's just to exaggerate the issue. Here's another example
Map: https://osu.ppy.sh/beatmapsets/1973616#mania/4097226, scroll speed 30

Low density part (start of map), Update FPS mostly stays at the limit

High density part (~5:20), Update FPS drops down to 180

In real gameplay (not watching a replay), these fluctuations manifest as perceivable "hitches" (dropping in smoothness) when a dense part is reached, which is highly frustrating as a player. I expect some degradation in performance when more notes are on screen, just not that much