RE: CPU Lag Spikes Still Evident; Rhythmic Reoccurrence in *any* ROBLOX game (Empty or Not)

[Juicy_Fruit]

This is a continuance of the following post: Lag Spikes -- MicroProfiler shows "Thread -Foreground"

The bug portrays a quick freeze congruently, there is a spike in CPU usage… while short and the rhythmic repeat time being around 10-20 seconds, still breaks fluid flow of gameplay. This ‘bug’ is never truly ending and occurs in all ROBLOX games so my assertion is that the cause of the freeze and spike is not that of poor code and script executions.

Additionally my brother who has same computer has been getting the same problem, we were worried that his CPU may have been degraded or some other facet was causing the problem, but extensive attempts to locate possible problems (W11 has been pretty bad in terms of bloat and whatnot, other games/applications outside the purview of ROBLOX had no problems) and testing the CPU/Hardware warranted 100% green on our end–it is ROBLOX

Additionally I didn’t notice problems on my end until after I was made aware of his problems…

System Specs
Windows 11 Home; Version 10.0.26100 Build 26100
Processor Intel(R) Core™ i7-14700F, 2100 Mhz, 20 Core(s), 28 Logical Processor(s)
Graphics Card NVIDIA GeForce RTX 4070 Ti SUPER
Ram 32 GB

Bios Up To Date and has been kept up to date with all updates.

Imagery of the rhythmic CPU spikes and thread halts (Public; Actual micro profiler files provided privately)

Expected behavior

CPU spikes (and with that, microfreezes during gameplay) should not occur in all ROBLOX games (empty ones also proved to procure the spikes).

The only situation this should occur is within a poorly optimized script execution…

Again, will be attaching microprofiler files–I don’t really know whats going on just that I can see its effect…

A private message is associated with this bug report

[newtonmetre]

Are you only seeing this when microprofiler is turned on? What if it’s completely off? (not running on the top of the screen either) - especially if you use another frame rate monitor/pacing utility (Win-G → performance → frame for one built into Windows)

[user0111]

I’m experiencing the same issue, and it also happens with the microprofiler off. The lag spikes did show up through the FPS monitor you mentioned.

This was taken on the home page in-app.

[Nathan30060819 (Wall_Dweller)]

ive also been getting this issue, but its only been in 1 game so far and theyve only lasted in about 1 minute waves

[DeliciousAppleb (huy)]

I also experience the same issue whether MicroProfiler is on or off. I’ve also tried running Roblox completely standalone—no other performance monitors or overlays like the Windows Game Bar (Win + G). The lag spikes consistently occur every 10–20 seconds, regardless of the game I’m playing or the graphics level settings.

I’ve attached a MicroProfiler screenshot showing one of the spikes. You can see that during these moments, the “Thread Foreground” section takes significantly longer to process, which I suspect might be related to the issue.

[newtonmetre]

We have MicroProfiler specific overhead (which is taking longer than we expect it to) in the Thread-Foreground that doesn’t happen if the MicroProfiler has been off since the start the application.

Once you start the MicroProfiler it will incur this overhead. Turning MicroProfiler off via the Escape menu or key combination will not clear this. Also note, we have a bug with MicroProfile’s visible menu where if you select “Off” it’s still on and it doesn’t clear the game settings file option - so it will auto restart.

Can you verify that MicroProfiler is not running via the key combination (platform specific but for windows it’s Ctrl-Shift-F6) - and then once you’ve done this, completely restart the client and make sure you don’t see the Microprofiler running. Then do the frame pace measurement as you’ve done via Win G → Performance.

For the record we know all of this is annoying and plan on fixing these usability bugs - as well as the potential overhead of the MP call.

[user0111]

Doing this doesn’t seem to have fixed the issue for me. Linking a video below just in case I’m doing it wrong.

The FPS overlay doesn’t seem to work well with Roblox, but I did notice several lag spikes before opening the microprofiler again in the video.

https://www.youtube.com/watch?v=07QQqqZUsKo

(Might be worth noting that I did try reinstalling roblox before this, including deleting the folder in AppData\Local. Still had the issue.)

[DeliciousAppleb (huy)]

I’ve followed your instructions:

Turned off the MicroProfiler using Ctrl + Shift + F6
Completely closed Roblox
Reopened Roblox and joined a game, ensuring the MicroProfiler was not running

However, I’m still experiencing the same issue. The lag spikes persist — the FPS occasionally drops from around 133–144 FPS down to 60–70 FPS, then returns to normal.

While the CPU usage in the Windows Game Bar (Win + G) performance overlay doesn’t show much of a spike, I do notice CPU spikes in the Roblox in-game performance stats during these FPS drops.

For reference, here are my device specs:

• CPU: Intel Core i7-13650HX
• GPU: Nvidia RTX 4050 Laptop GPU
• OS: Windows 11 24H2 Home Single Language

[Juicy_Fruit]

Yes this issue occurs when all performance stats/micro-profilers systems are off.

I only used these visuals to demonstrate the spiking actually occurring–though I could’ve used a basic video, this was just easier (I can get a video though).

I should also mention that this all seems to have started sometime after latest windows 24h2 updates… I cant exactly pinpoint if it is the culprit? but June-July builds may need to be looked into?

I can also say that studio testing has no spiking whatsoever if that helps

[newtonmetre]

Ok thank you for the updates, this really helps narrow down the potential cause.

[Instance_Brick (Instance)]

On version 225e87fdb7254f64 it seems the issue is persisting, this build was just released yesterday.

Its still the little spikes, then every so often a huge spike. All caused by thread - foreground

(This is a repost from the last post)

[newtonmetre]

We have some changes going in targeting the 683 release, while won’t fix the issue, will help us narrow down where it is. When this release lands please retake the MP captures!!

[BreezeOnTheDoor (Unceen)]

This also occurs for me. It occurs whether or not microprofiler is enabled or not. It seems pretty consistent and occurs in periodic waves. Not sure but the frequency of these spikes seem to increase slightly as the game goes on. Occurs in both studio and roblox in game.,

[user0111]

Here’s what the microprofiler shows for me now.

[Juicy_Fruit]

microprofile-20250725-193911.html (1.5 MB) – base roblox player allows micro profiler

microprofile-20250724-174140.html (6.3 MB)

[user0111]

Issue seems to be fixed for me now, if you guys did something.

[Juicy_Fruit]

yes it seems fixed.. original problem is not active, not sure if anything comes up in mp that indicates what was solved

microprofile-20250801-202151.html (6.0 MB)

[AkaWhats (Aka)]

The issue seems to be fixed for me for an hour or so, but it was happening earlier today which was strange.

microprofile-20250803-155312.html (6.3 MB)

Frametimes stayed consistent whereas before there would be a random spike every so often. I think this report is directly related by the way: Huge frame spikes due to CoreScripts "SchedulerHostConfig.default" taking hundreds of milliseconds

[AkaWhats (Aka)]

After looking through other bug reports, I think I found the issue.

Frametime spikes decimating FPS by 5x

Did some troubleshooting so that the Roblox staff don’t have to; as a result I should expect the bug not to persist for long. The stutters originate from launching a game from the Roblox app’s homepage. Clicking on an experience and then hitting play takes you away from the homepage, eliminating any dynamic updates in the background related to updating information (IE. friend status updates, friend experience status updates), so this is a safe way to play experiences without incurring any stut…

Launching a game through the app causes the frequent lag spikes to occur, but launching a game through the website has no issues. I think I do remember launching game’s through the website and still having the issue however, so part of the problem might have been fixed but not all of it.

[BreezeOnTheDoor (Unceen)]

The issue is that it also occurs on studio. I also launched with the website and it still lagged, I don’t think this is the solution.