On mobile devices (only tried so far on Samsung Galaxy S7), displaying new in-game chat messages causes massive lag spikes. Processing a single message can take 1-2 seconds, freezing the entire game. This is particularly noticeable for longer chat messages.
Samsung Galaxy S7
4 GB RAM
Roblox app version: 2.373.280591
Here’s one of the data points from using the client microprofiler. Notice the ChatMain chunk takes close to 1.5 seconds for a single frame. This lines up with when another player chatted.
- Create an empty baseplate from the template (mine is here: https://www.roblox.com/games/2915941557/Baseplate)
- Get 10-15 players in the game in an online server, chatting occasionally
- When other players chat, you see a placeholder “—” that is the length of the full chat message, and then the FPS drops close to 0 and everything freezes. When it unfreezes, the placeholder is replaced by the actual message. It seems to do this more frequently when there are large numbers of players chatting.
This happens regardless of whether bubble chat is enabled or disabled, so it only seems to be related to the chat on the upper-left corner of the screen.
More detailed video of the microprofiler that shows how long each operation takes.
Seems to be primarily caused by the “Text Shaping + Layout” step.