Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] Daily Builds => Topic started by: Majeranek on 2024-10-23, 17:55:55
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Hmm.. am I the only one that noticed that with latest Corona build the interactive is really slugish? When I have material editor opened it's even worse. I don't know what's wrong with that but IMO every new version of corona the interactive is becoming slower.
The scene isn't complicated. It's just single object with bunch of lights.
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Hmm.. am I the only one that noticed that with latest Corona build the interactive is really slugish? When I have material editor opened it's even worse. I don't know what's wrong with that but IMO every new version of corona the interactive is becoming slower.
The scene isn't complicated. It's just single object with bunch of lights.
Could you share an example recording showing the issue and a comparison with Corona 12 HF1?
I am asking because we are investigating some performance issues, but before I share anything I would first like to see what exact kind of "sluggishness" you are getting.
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Oh, I reverted everything back to 12 HF1. Everything is fine now. It was like few ms lag on everything, orbiting, moving mouse, changing values.
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Please, send the scene (or better the scene with the recording), so we can have a look at it.
If it is not found and resolved, it will most probably stay there and become an inconvenience later on.
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Oh, I reverted everything back to 12 HF1. Everything is fine now. It was like few ms lag on everything, orbiting, moving mouse, changing values.
If you are getting this kind of viewport lag/stutter for example when panning or rotating, it is most likely a 3ds Max 2025 issue. It happens with any renderer, even when Corona and V-Ray are uninstalled. I was also unable to reproduce it in 3ds Max 2024. This is already reported to Autodesk.
If you are getting something else, please do let us know. As Aram said, a scene and a video demonstrating the issue would be perfect.
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i was using max 24 - its not a max 25 issue. definitely a corona issue.
Oh, I reverted everything back to 12 HF1. Everything is fine now. It was like few ms lag on everything, orbiting, moving mouse, changing values.
If you are getting this kind of viewport lag/stutter for example when panning or rotating, it is most likely a 3ds Max 2025 issue. It happens with any renderer, even when Corona and V-Ray are uninstalled. I was also unable to reproduce it in 3ds Max 2024. This is already reported to Autodesk.
If you are getting something else, please do let us know. As Aram said, a scene and a video demonstrating the issue would be perfect.
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Hi Devs
3 videos comparing 07.30 daily, 10.23 daily and Corona 12HF1. You can see the FPS difference. On the latest daily, even on my other monitor, things like youtube start to stutter which indicates to me it interferes with the GPU somehow?
All in all, the latest dailies are much slower - the IR buckles the PC (not just corona).
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Thank you for the videos! We will see if we can reproduce a similar issue. Is there a chance you could share your scene with us?
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I cant sorry - however i can confirm it does it with all scenes.
Thank you for the videos! We will see if we can reproduce a similar issue. Is there a chance you could share your scene with us?
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I cant sorry - however i can confirm it does it with all scenes.
You mean even in very simple scenes? I'm on Max 2024 as well and i have no such issues with Corona 13, including latest build. Maybe it's processor, video card, particular Windows build? It's probably worth to provide as much info as you can.
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I am getting a similar kind of slowdown in IR when the denoising is set to Intel GPU AI. Maybe related to GPU age/drivers?
Majeranek maybe try disabling it and report back!
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I was unable to reproduce this. If anyone is having similar problems, please let us know here.
Ryzen 3900X
RTX 4070
3ds Max 2024
Default render settings (Optix as the IR denoiser)
V12 HF1:
23.10 V13 daily:
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Same performance here when IR denoiser is changed to Intel.
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I use a TR - could it be that?
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(continuing in support ticket 307305)
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I did notice slowdowns when IR is running in Corona 13. Slowdowns are not in the viewport, but rather in slate material editor. When IR is running everything in SME is more sluggish - dragging nodes around, connecting node handles, almost every operation needs to be tried 2-3 times before succeeding. Not a deal breaker, but certainly adds up to quite frustrating experience. SME was never smooth in Corona, but in V13 it's even worse than usual.
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What is your CPU Romullus, and could you share a sample screen capture?
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Ryzen 5950x
I will try to record some screen capture some time later. I will also try to go back to Corona 12, just to check if slowdown is real and not something i imagine.
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i realise hte latest daily may not have addressed the issue of the slowdown - but wanted to confirm and let you know i installed it and its still slow.
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Has this issue been addressed yet in the latest release?
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Update from my side, 12 update 1 - still a huge slowdown in max. Even settings tooltips appear/disappear very slowly. Other software like chrome is slow as well.
intel 7980xe, 36 threads. By default # of threads override is set to -1. Reducing this number makes things more responsible (while slowing down render), BUT even with -18 (half) 3dsmax still utilizes 90-95% CPU. At -30 it uses 80-90% at first passes dropping to 37-40 in a few seconds. At -35 (so only one thread) max uses 60-70% at the start and drops down to 17-20%.
The best setting for me so far is -6. All higher is too slow, and reducing it below 6 has no noticeable effect.
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I am experiencing the same slowdowns with the most recent update (Corona 12 Update 1).
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Seems like the problem exists not only with IR, but also with production render. I started rendering and even the text I'm typing right now appears with significant delay. Everything is so slow - I had 2 max opened and after I started rendering in one of them, I tried to close another. Saving the scene before closing took almost a minute instead of a few seconds. The scenes are quite simple, 30mb in size (with compression). Without rendering it takes just a few seconds to save.
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hey what version of windows do you use?
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Windows 10Pro 22H2
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I wonder if anyone experiencing this sluggishness has looked at their GPU VRAM usage in Task Manager? That's when my viewport\slate\UI seems to come to a screeching halt for me lately. Scenes that shouldn't really be maxing out VRAM still sometimes do. Very odd. Saying things are sluggish is an understatement, and when IR starts it can get nearly unusable. Even in isolation mode with one object I still get 95% VRAM usage, although perhaps Max doesn't clear VRAM in isolation mode, can't say I've tested that before.
Windows 10
Max 2025
Corona 13 DB from July 30
Latest Forest Pack
RTX 2080 Ti driver 32.0.15.6094
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I wonder if anyone experiencing this sluggishness has looked at their GPU VRAM usage in Task Manager? That's when my viewport\slate\UI seems to come to a screeching halt for me lately. Scenes that shouldn't really be maxing out VRAM still sometimes do. Very odd. Saying things are sluggish is an understatement, and when IR starts it can get nearly unusable. Even in isolation mode with one object I still get 95% VRAM usage, although perhaps Max doesn't clear VRAM in isolation mode, can't say I've tested that before.
Windows 10
Max 2025
Corona 13 DB from July 30
Latest Forest Pack
RTX 2080 Ti driver 32.0.15.6094
If possible, please try with the latest stable release - Corona 12 update 1 - and let us know if you are still experiencing the sluggishness.
There is already a similar report being investigated.
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I wonder if anyone experiencing this sluggishness has looked at their GPU VRAM usage in Task Manager? That's when my viewport\slate\UI seems to come to a screeching halt for me lately. Scenes that shouldn't really be maxing out VRAM still sometimes do. Very odd. Saying things are sluggish is an understatement, and when IR starts it can get nearly unusable. Even in isolation mode with one object I still get 95% VRAM usage, although perhaps Max doesn't clear VRAM in isolation mode, can't say I've tested that before.
Windows 10
Max 2025
Corona 13 DB from July 30
Latest Forest Pack
RTX 2080 Ti driver 32.0.15.6094
If possible, please try with the latest stable release - Corona 12 update 1 - and let us know if you are still experiencing the sluggishness.
There is already a similar report being investigated.
Ok will do. For what it's worth I just downsaved the file to Max 2024 and am seeing about 3.5gb less VRAM usage which is crazy. Same corona DB version between the two.
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Monitoring VRAM is good idea. I use 16+ GB VRAM GPUs but even then I still use only 1024px Viewport setting (remember CoronaBitmap uses the Environment setting, so just set 3x1024px and enjoy looking at blurry shit in viewport :- D !)
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I have a really simple scene with basic materials (no textures used, only Corona basic materials), and my VRAM is almost full (7.4 GB out of a total of 8 GB is used). Even with this scene, using interactive is problematic and laggy. I have an RTX 3070, and my CPU is a Core i9 13900 with 64GB of RAM.
I never had this issue with previous Corona versions, even in much heavier files.
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I have a really simple scene with basic materials (no textures used, only Corona basic materials), and my VRAM is almost full (7.4 GB out of a total of 8 GB is used). Even with this scene, using interactive is problematic and laggy. I have an RTX 3070, and my CPU is a Core i9 13900 with 64GB of RAM.
I never had this issue with previous Corona versions, even in much heavier files.
What Max version, just out of curiosity?
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Monitoring VRAM is good idea. I use 16+ GB VRAM GPUs but even then I still use only 1024px Viewport setting (remember CoronaBitmap uses the Environment setting, so just set 3x1024px and enjoy looking at blurry shit in viewport :- D !)
Have you tried either 3090 or 4090 for the 24gb memory? I've been eyeing one of those as an upgrade from my 11gb 2080 ti. The 3090 seems like a decent price point (~$1500 USD) considering the other factors besides VRAM don't impact performance that much...
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I have a really simple scene with basic materials (no textures used, only Corona basic materials), and my VRAM is almost full (7.4 GB out of a total of 8 GB is used). Even with this scene, using interactive is problematic and laggy. I have an RTX 3070, and my CPU is a Core i9 13900 with 64GB of RAM.
I never had this issue with previous Corona versions, even in much heavier files.
What Max version, just out of curiosity?
I'm using max 2025.3, the most recent update
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I did a test with a scene on my work PC (with an RTX 3070) and my home PC (with an RTX 3090). On the work PC, the Vram usage is 7.5 GB out of 8 GB and I will encounter a lot of slowdowns during interactive renders or even in material editor for a few seconds. On the home PC, the VRAM usage is 4.6 GB out of 24 GB and I don't encounter slowdowns. Both are on the latest version of 3ds Max and are using Corona's latest release. No other program is running in the background. I don't recall having issues like this using any of the previous versions of Corona and even on my home PC, 4.6 GB of VRAM usage for a scene that simple is a bit much. I will try to test the same scene on another PC running an older version of the Corona with an RTX 2070 Super and will report back.
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I did a test with a scene on my work PC (with an RTX 3070) and my home PC (with an RTX 3090). On the work PC, the Vram usage is 7.5 GB out of 8 GB and I will encounter a lot of slowdowns during interactive renders or even in material editor for a few seconds. On the home PC, the VRAM usage is 4.6 GB out of 24 GB and I don't encounter slowdowns. Both are on the latest version of 3ds Max and are using Corona's latest release. No other program is running in the background. I don't recall having issues like this using any of the previous versions of Corona and even on my home PC, 4.6 GB of VRAM usage for a scene that simple is a bit much. I will try to test the same scene on another PC running an older version of the Corona with an RTX 2070 Super and will report back.
Can you please also check the GPU usage with IR, if any of the AI denoisers are enabled for IR? Check optionally with earlier versions (v12 hf1, v11 hf2 etc.) too.
For IR sluggishness in v12 update 1 - it may be due to slightly higher CPU than v12 hf1, so you should see higher speed (ray/s) stats for IR in v12 update 1 than in v12 hf1. If you can confirm this, I will appreciate it and it will help with troubleshooting too.
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I wonder if anyone experiencing this sluggishness has looked at their GPU VRAM usage in Task Manager? That's when my viewport\slate\UI seems to come to a screeching halt for me lately. Scenes that shouldn't really be maxing out VRAM still sometimes do. Very odd. Saying things are sluggish is an understatement, and when IR starts it can get nearly unusable. Even in isolation mode with one object I still get 95% VRAM usage, although perhaps Max doesn't clear VRAM in isolation mode, can't say I've tested that before.
Windows 10
Max 2025
Corona 13 DB from July 30
Latest Forest Pack
RTX 2080 Ti driver 32.0.15.6094
If possible, please try with the latest stable release - Corona 12 update 1 - and let us know if you are still experiencing the sluggishness.
There is already a similar report being investigated.
Got a chance to test this yesterday. Moving from the July 30 build to the stable Corona 12 Update 1 resulted in the same VRAM usage but did add an insane sluggishness to my UI\mouse that I hadn't experienced before. Even with IR not running my mouse would freeze and pause. Just running the cursor over complex objects in the viewport (not even selecting them) was enough to cause mouse lag. Very odd.
I downgraded back to the July 30 DB and all that went away. FWIW the scene I was in would result in a hard crash upon opening with the July 30 build after having been saved in Update 1. I merged it into a new scene and that crash went away.
As for VRAM, Max 2025.3 seems to result in 3-4gb more VRAM usage than 2024 even with empty scenes. I haven't tried it with Corona uninstalled fully but perhaps its a Max bug. Sepia21 I'd be curious if 2024 gives you less VRAM usage like me *shrug*
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I repeated the test on three PCs, and the results are as follows:
PC 1: Equipped with an RTX 2070 Super, running Corona 12 HF1 on Max 2025.3.
Opened Scene: Consumed 1.4 GB of VRAM.
Interactive Rendering: No change in VRAM consumption.
PC 2: Equipped with an RTX 3070, running Corona 12 Update 1 on Max 2025.3.
Opened Scene: Consumed 6.1 GB of VRAM.
Interactive Rendering: Increased VRAM usage to 6.5 GB.
After Stopping Interactive: VRAM usage rose further to 7.2 GB.
PC 3: Equipped with an RTX 3090, running Corona 12 Update 1 on Max 2025.3.
Opened Scene: Consumed 4.6 GB of VRAM.
Interactive Rendering: Reduced VRAM usage to 4.1 GB.
After Stopping Interactive: VRAM usage decreased further to 3.4 GB.
All PCs are running the same version of Windows 11 (24H2).
Regarding tests with Max 2024:
Unfortunately, I have Max 2024 installed only on PC 3 (RTX 3090), so I cannot replicate the test across all PCs. However, I noticed that Max 2024 consumes less VRAM compared to Max 2025. Running the same test on Max 2024 with the latest version and Corona 12 Update 1 resulted in:
Opened Scene: Consumed 2.4 GB of VRAM.
Interactive Rendering: No change in VRAM consumption during or after stopping interactive rendering.
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I am experiencing exactly the same problems mentioned by Danio1011 using Corona v12 update 1 namely:
1) A slowness of the 3DSmax interface with a lack of fluidity.
2) This slowness appears especially during renderings (both in interactive rendering and production rendering..)... During renderings (production render) Windows becomes subject to slowness, internet browsing is jerky, everything becomes less fluid whereas with the previous version of Corona I had never encountered this kind of problem....
3) Like Danio1011 I noticed that if I save a file with Corona V12 update 1, it is impossible for me to open it with Corona 12 Hotfix 1 (and the "merge" also crashes)... Once Corona V12 Update 1 is reinstalled I can open these files again....
These slowdowns of the 3DSmax interface (2024 and 2025) under Corona 12 update 1 (especially during renderings) are extremely penalizing because all Windows is slowed down... Furthermore, by observing the task manager I observe that the processor, during renderings, to completely random power drops...
I specify that I work on a Threadripper 3990X station with 256 GB of ram and a 2080 Ti (latest drivers installed), under updated Windows 11.
Thank you very much for your attention.
Mienda
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The sluggishness is known for high core machines and is being investigated.
Backward compatibility was never guaranteed - Corona 12 Update 1 saved scenes are not guaranteed to work with Corona 12 Hotfix 1, so please back up the scenes. Corona 12 Hotfix 1 saved scene should work fine with Corona 12 Update 1.
Please, whoever is investigating this: please check if IR is faster (more rays/s), for any given scene, in Corona 12 Update 1 than in Corona 12 Hotfix 1. If so, please confirm it, so we know that we are on the right track.
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The sluggishness is known for high core machines and is being investigated.
Backward compatibility was never guaranteed - Corona 12 Update 1 saved scenes are not guaranteed to work with Corona 12 Hotfix 1, so please back up the scenes. Corona 12 Hotfix 1 saved scene should work fine with Corona 12 Update 1.
Please, whoever is investigating this: please check if IR is faster (more rays/s), for any given scene, in Corona 12 Update 1 than in Corona 12 Hotfix 1. If so, please confirm it, so we know that we are on the right track.
Can you provide a link for V12 HF 1? It's not listed under 'older versions' on the chaos download page and the changelog forum pages don't link directly to it that I can find. Going to try rolling back from the July 30 build to see if my VRAM drops like Sepia's results.
Thanks
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The sluggishness is known for high core machines and is being investigated.
Backward compatibility was never guaranteed - Corona 12 Update 1 saved scenes are not guaranteed to work with Corona 12 Hotfix 1, so please back up the scenes. Corona 12 Hotfix 1 saved scene should work fine with Corona 12 Update 1.
Please, whoever is investigating this: please check if IR is faster (more rays/s), for any given scene, in Corona 12 Update 1 than in Corona 12 Hotfix 1. If so, please confirm it, so we know that we are on the right track.
Can you provide a link for V12 HF 1? It's not listed under 'older versions' on the chaos download page and the changelog forum pages don't link directly to it that I can find. Going to try rolling back from the July 30 build to see if my VRAM drops like Sepia's results.
Thanks
I will try bumping this, so it appears in older download options in the website.
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It seems that the backwards compatibility problem between Corona 12 hotfix 1 and corona 12 update 1 comes from the Corona camera because the scenes recorded in corona 12 update 1 crash all the time unless you don't merge the cameras (if you merge the scene without the cameras, it opens without problem...).
Finally, if the slowness problem on machines with many cores is a known problem, I had never encountered it before using Corona 12 Update 1....
Thank you for your attention
Mienda
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Little update on this (responsiveness drop/slowdown with IR, v13 DBs, after some point, and v12 update 1):
We narrowed down the issue and have found one of the reasons of this, and it has been fixed internally.
There are some leftovers/cases where responsiveness drop can be observed and these are being handled as well.
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great to hear! when can we expect a fix? i assume it will be a hotfix?
Little update on this (responsiveness drop/slowdown with IR, v13 DBs, after some point, and v12 update 1):
We narrowed down the issue and have found one of the reasons of this, and it has been fixed internally.
There are some leftovers/cases where responsiveness drop can be observed and these are being handled as well.
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Little update on this (responsiveness drop/slowdown with IR, v13 DBs, after some point, and v12 update 1):
We narrowed down the issue and have found one of the reasons of this, and it has been fixed internally.
There are some leftovers/cases where responsiveness drop can be observed and these are being handled as well.
Hi,
The fast IR was always like the "heart" of Corona, and now it beats slowly. Are there any plans for HotFix for update 1?
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As the holidays approach, we will probably try to do a DB on the second half of January, but nothing specific for now.
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Just confirming post holiday that this is the plan - expect to see daily builds soon, so you can test out the fixes and let us know if the issues are resolved, then somewhere in the second half of January (if testing goes well of course), the final official hotfix version will be out.
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I really hope that in the next version, the corona team can solve the problem of sudden full memory load. When working ona project, I am always afraid that the memory is suddenly full loaded and stuck, which will affect the project progress. Thank you to the corona team
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Hey everyone, who experienced general slowdown of machine while rendering (IR or production) with Corona.
This should be addressed in the first daily build of 2025 (https://forum.corona-renderer.com/index.php?topic=43295.msg230430#msg230430)!
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A lot of us are having these slowdowns in a production environment on live jobs so dailies aren't really a practical solution. Any hotfixes planned?
Apologies I clicked your link after posting and saw a hotfix is planned. Thank you
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Hey is this necromancy? (5-6 month old topic)
Anyway, I didn't want to start a new topic, but recently my good old Threadripper 2970wx is choppy when I start rendering in Corona.
Was there any significant change in that regard? What could be the possible reason?
I used to run OBS relatively smoothly, stream and render at the same time. Now as soon as I turn on Interactive render, even with the simplest of scenes, my PC is visibly less responsive its like Im wrestling with Max.
Temps seem to be fine, I haven't changed anything significant, and still, I need some help.
Any ideas what I can try?
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Hey hey, which exact build are you using?
There was an older build in which some people reported slowdowns. But later it got resolved on its own. Try using the newest daily build available and make sure you have your Windows fully updated.
If that's not helping, could you record a short video showing the slowdown and share it here?