Playing multiple notes/sounds at once lags the project

Continuing the discussion from You Can Talk About Your Hopscotch Coding Here 27 [OFFICIAL]:

Your username: Rawrbear

What kind of device are you using?: iPhone 8

1 sentence description of the problem: When playing notes at the same time, it causes a bunch of lag, but only on the mobile version of Hopscotch.

Steps that the Hopscotch team can take to reproduce my problem every time:

So there would have to be a project with more than one section of music playing at the same time. Basically, when two or more notes play on the same frame, it causes a performance hit.

This can be observed in the sound test portion of @Awesome_E’s LagTest project, on any mobile device - playing many notes at a time freezes the project for a solid 20-30 seconds on my device - but this is not reproducible on the web (you’ll have to wait a minute or two for the other tests to finish first though).

Here is a picture of my lag test/benchmark results, ran on my phone.

The final dip that goes to the bottom of the screen in the picture is the sound test.

I expected this to happen:

All notes play without any performance struggle, so there’s no lag.

But instead this happened:

The engine lags really hard when multiple notes play at once.


it affects a lot my musics when i’m adding strings into it


Oh no that isn’t good at all


@Yuanyuan and @AwesomeOnion, hopefully this bug report sheds some insight. Thanks a bunch!


Thanks for letting us know!


yeah I cant play more than 3 notes without the fps dropping below 50ish (that’s without other objects)


(Just a quick note)

This only occurs on the iOS app, not the web


Yep, can verify. Thanks for the extra clarification :+1:

Here’s a lag test running on the web player in Firefox from my laptop. It’s running off my integrated graphics, which hit 100% use as of doing this test, so it’s safe to disregard the FPS dips from other tests. :sweat_smile:

It’s more important to note that there was no long freeze whatsoever during the sound test on the web player. It took maybe 2 seconds to get through, which is not a problem whatsoever compared to 30 seconds of freeze time on the mobile version of the app.


Interesting bug, don’t know how I haven’t noticed this before.
I hope the problem is pinpointed, and we can continue to listen to music projects lag-free.


Hi maybe let’s not tag awsomeonion since she isn’t on very much I’ll gbot now


I didn’t realize that; thanks! In general though, it doesn’t hurt to let staff know about a bug like this. :+1: