Server Authority mispredictions scale with client FPS under high latency

Summary
I’m seeing a strong correlation between client frame rate and misprediction frequency when using Server Authority under high-latency conditions. At frame rates above 60 FPS, mispredictions become frequent enough to noticeably degrade gameplay feel. Capping at 60 FPS under the same network conditions largely resolves the issue, which points to a bug in how Server Authority handles prediction/reconciliation as a function of client tick rate rather than a pure latency problem.

Environment

  • Client ping: 50+ ms (reproduces across high-ping conditions generally)
  • Client frame rate: above 60 FPS (issue present) vs. 60 FPS (issue largely absent)

Steps to reproduce

  1. Connect to a server with moderate to high ping (~50+ ms) or simulate in studio via network simulation.
  2. Run the client at a high frame rate (above 60 FPS).
  3. Observe frequent mispredictions during normal gameplay. Also causes inputs to feel delayed and less responsive.
  4. Cap the client to 60 FPS under the same latency conditions and observe that mispredictions are significantly reduced.

Note: Reproducible on a blank baseplate

Impact
Players on higher-refresh-rate setups get a worse experience than those capped at 60 FPS, which is the opposite of what we’d expect. This affects any player with both high ping and high FPS.

Expected behavior
Misprediction/reconciliation behavior should be independent of client frame rate.

Actual behavior
Misprediction frequency scales up with client frame rate above 60 FPS, making the game feel bad despite latency being unchanged. At 60 FPS the experience is much smoother even at the same high ping.

A private message is associated with this bug report

11 Likes

I’ve spent about a week trying to reduce mispredictions unsuccesfully and just setting the FPS to 60 got rid of so many. This has to be a recent regression because I can’t remember it being this bad before

2 Likes

Got this bug too, I thought this was a normal thing regarding server authority but seems to not be the case:

2 Likes

We have a fix out for this. Look for this to improve in 732 in the coming days. Let us know if this doesn’t help. Sorry for the trouble and thank you so much for the report!

5 Likes

Awesome, thank you for the quick fix and for your update on this matter.

1 Like

Did this get rolled out in 732? @welblander

Really struggling to port our game over to Server Authority due to this.

1 Like

Doubling this, Haven’t noticed much improvements.

1 Like

It seems to be fixed on the Roblox game client but I haven’t tested to see if it is still an issue in studio. I’ve been playing at 60 fps in studio still. Based on what y’all are saying it seems like it could still be an issue in studio.

Personally I think the delay has halved but theres still delay

inputactions are delayed too even if they should be client authoritative, even for local scripts they are delayed, the only way to get an input without delay is with userinputservice

I’m experiencing the same thing

Seems to be announced in release notes 733.

Image of the release note talking about the issue being announced in pending on release note 733