SDK 36 performance

Please provide the following:

  1. SDK Version: 36
  2. Platforms(Android/iOS/web/all): iOS

Has anyone noticed a slowness in their UI after upgrading to sdk 36? For me this is only noticeable in dev mode. But with sdk 35, same code, no issues at all. All animations and panResponder (scaling) were fast and smooth before and now with just upgrading to v36, it’s all sluggish and the JS frames plunge to 0 sometimes. Before they stayed almost always close to 60.

I’m not even sure where I need to start debugging this. Even simple flat lists are showing drops in the JS frames. I am not using any console.logs and looking at the Performance section on Expo did not fit any of my scenarios.

Is this somehow related to Fast Refresh?

I also noticed that sdk 36 is less responsive as well as crashing with no errors. Especially with longer FlatList that had no problems in SDK 35! So far 36 seems unstable.
Any ideas anyone, how to debug these random crashes that don’t have errors?
It looks to me like some memory leaks!

Yes, I got the similar experience. not sure it is about RN0.6x issues.
Some bugs show again in SDK 36 like component insides scrollview would freeze after switching bottom tab during scrollview is under momentum

anyone from Expo able to help here please?

Hi there,

I’m facing significant stuttering, lag and performance issues after upgrading (from SDK 32, 33, 34, 35) to SDK 36 (RN 0.6x) as well.

They seem to be mostly related to Android. Some of them are very obvious in dev mode but also noticeable in release builds. Other issues are only apparent in release builds and do not even show up in dev mode :roll_eyes:. To make it even harder to debug some of them are only triggered by high memory pressure and/or when many views are mounted.

First I tried ejecting expo projects to expoki/bare and compared different versions and runtimes of android-jsc, hermes and v8 as I thought it could be related to garbage collection. Some memory improvements can be seen with Hermes or the v8 runtime but they do not solve these issues.

After that I tried different RN versions and my issues start to show up after upgrading from RN 0.59.10 to 0.60.0. So I think they are not directly related to Expo itself but moving to RN 0.6x in SDK 36 seems to introduce those issues.

Is everything ok with the Expo team? Haven’t heard back from anyone on their end on any of my tickets here…

Performance issues are especially tricky to look into. One thing that may help save some time in identifying which components could be causing the issue is to use the profiler in the react native debugger

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hi, i just notice a probleme on SDK 36 (i don’t notice that on sdk35).

My app is a landscape orientation.
so when i launch my app in portrait view (first time), the size of component are not like it should be.
when i reload or switch background mode to main, all become ok.
i didn’t have this issue before (responsive error ?)

i get the same issue in orientation portrait app when i launch the app in the landscape view

the error appear in dev mode, not in production mode…

This thread is about sdk36 performance… Not responsiveness of display