updateInvalidatedFastClusters taking really long to complete, causing low fps

Reproduction Steps

Repro steps: Spawn as SD / Security Department and shoot. Watch FPS drop. (note this was not an issue before and the game has not been updated in two months)

Repro steps (unfortunately only for Roblox staff): Select the Red Wolves team and spawn in, shoot. FPS should drop. Same situation as the game linked above.

Repro steps (only Roblox staff can join): Spawn as SC / Security Divisions > Security Corps and shoot, or walk around and notice the lag spikes. Watch FPS drop. (note this was not an issue before)

Expected Behavior
I expect updateInvalidFastClusters to take at most 4ms or around this value, but nowhere any value as close as 40ms or at some points 110. I could only find this post referencing this microprofiler bar, but the issues seem very different.

Actual Behavior


(images taken through the microprofiler on all games linked above)

Issue Area: Engine
Issue Type: Performance
Impact: High
Frequency: Constantly
Date First Experienced: 2021-10-22 00:10:00 (+00:00)


Thanks for reporting this, I will follow up with you privately for more info.


Hey there, sorry for bumping this. Have you managed to find some fix for this? I am currently experiencing the same issue in a prototype I’m building, and I’m not sure what is causing the huge updateInvalidatedFastClusters, nor how to fix it.