High CPU usage / low FPS

[olessavluk]

Hey,

I've noticed significant lag when scrolling over list of banks:

CPU/threads/FPS chart

Video with visible lag (see how long it takes for images to render)

file.mp4

Do you know what could be causing this? Noticed images are "blinking" during the scroll maybe there too much encoding/resizing happening on every element instead of once?

[tl-keenen-charles]

Hey Oles, I haven't seen this issue before. You're using the react native sdk right? Could you also share what device (or emulator) and OS version you're testing on?

[olessavluk]

yeah, latest react native sdk

I've tried multiple device, seems like all of them have same issue:

• pixel 4
• pixel 4a
• samsung galaxy a50

it's also mostly visible on first swipe, later in 5-10s becoming faster

[tl-keenen-charles]

Thanks for the info! We have been able to reproduce it now. Will look into this and get it fixed it in a future release.

[tl-keenen-charles]

Hey, I've looked into this issue and it seems to occur when running the SDK in debug mode on Android due to some overhead that affects the performance of lazy layouts. The issue should go away when you run the app in release or profileable mode.

[olessavluk]

Just tried running release build made via yarn react-native run-android --mode release seems to be same. Also used DemoApp from RN package to make sure there are no interference with my app.

CPU/threads/FPS chart

Video with freezes at the start of scroll

file.mp4

Device used: Galaxy A50 (which is considered median peformance wise)

Compared with Gmail app - FPS also drops to ~40, but scroll is smooth all the time despite much larger list. So it's not that significant as I thought, but still feels too much for such a small list

CPU/threads/FPS chart when scrolling/navigating Gmail app

[tl-keenen-charles]

Can you share which tool you're using to monitor performance?

[olessavluk]

I was using https://docs.flashlight.dev/