Severe lag spikes when moving the mouse in Studio

Bug Reports Studio Bugs
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#1

In Studio, moving the mouse cursor in the viewport while providing no other mouse inputs causes lag spikes on a consistent period of about once every second. These spikes occur in both play solo mode and in Studio as a whole, and they do not occur unless the mouse is being moved over the 3D viewport.

I provided repro steps at the very bottom of the post.

I made sure to:

  • Disable all my plugins including any local plugins & restart Studio
  • Restart Windows before testing
  • Test in a Baseplate

I timed these spikes and observed the spikes getting more severe the longer the mouse is consistently being moved for (By about 21 seconds, I had counted 21 spikes, but the spikes began taking full seconds which prevented me from making consistent measurements past that).

These spikes appear as large time gaps between data in the microprofiler (the spike is not attributed to any bars in the microprofiler). It appears that the main thread hangs, while some threads like FMOD and RakNet threads continue to run unaffected.

The spikes also only occur if no other mouse input is given. For example, holding mouse button 3 (middle mouse), mouse button 2 (right click), mouse button 1 (left click), or even mouse buttons 4 or 5 (forward/backward in history in web browser, no effect in Studio) causes these spikes to vanish.

Observed Microprofiler gaps during spikes (FPS unlocker enabled):

image
image1920×996 211 KB

Microprofiler dump (FPS unlocker enabled):
microprofile-20231121-131703.zip (9.1 MB)

Repro steps

Enabling FPS unlocker makes the spikes significantly more pronounced. They are there even without an FPS unlocker though.

The spikes can be quickly reproduced like so:

  1. Open a baseplate.
  2. Hold a movement key such as D.
  3. Wave the mouse back and forth without pressing any other buttons.
  4. Large lag spikes will be observed.
10 Likes
#2

Thanks for the report! We’ll follow up when there’s any update on the issue.

3 Likes
#3

This is continuously going on so I would suggest fixing it quickly since it would get lots of downtime for Roblox studio users.

3 Likes
#4


This has been happening for a while now.

#5

I’m now experiencing this as well. I first noticed it happening while in Test mode and doing firstperson/shiftlock and then quickly looking around, but it doesn’t happen in thirdperson. It seems like it lags whenever the mouse is moving over the viewport as long as you aren’t clicking on anything. Very strange, and very aggravating.

2 Likes
#6

Just experienced this today. From some research, it looks like this is related to the mouse input polling rate. Though, when I adjusted the polling rate switch on my gaming mouse, it didn’t seem to make a difference.

I also noticed that the camera controls were acting strange and erratic when panning in testing mode.

I was able to apply a temporary fix by switching to a different mouse, but this is not a long-term solution. The mouse worked just fine yesterday, and I did not install any new drivers.

Hopefully a fix will come out for this soon!

2 Likes
#7

I’ve started to encounter this issue in studio test mode. It doesn’t seem to occur in solo mode though.

2 Likes
#8

Something I neglected to mention is that this only happens in testing mode exclusively for me, as well.

#9

This has also been happening to me recently after installing a new graphics card. Only happens in one game, and doesn’t lag if i hold down a mouse button or keep the mouse still. Only lags when i dont click any mouse buttons while moving.

In this video, i stop lagging whenever i hold down a mouse button, but when i release it my frames drop significantly.

Experience Link: BH - Roblox

1 Like