Rendering performance in Vector feels about 3-5x slower than the vanilla react example.

[ara4n]

No description provided.

[ara4n]

This is really painfully obvious when trying to resize the window (its trivial to max out 8 cores at 100% CPU just by rerendering), or using the app on Mobile Safari, where everything is sluggish as all hell.

[Half-Shot]

This is presumably no use to anyone anymore?

[turt2live]

It's slow.

[Half-Shot]

Do we not have a more targeted issue for "It's slow" than a issue about Vector in 2015 based off a old react example? Or put another way, is this issue helpful?

[turt2live]

tbh @lampholder would be the judge of how helpful an issue is, but in practice Riot is incredibly slow at rendering things (hundreds of milliseconds) which is problematic.

[Half-Shot]

Fair, I agree with the slow. I just think this isn't a great issue :)

[jryans]

I also agree this issue isn't great... It's not very actionable as it stands.

It's quite general and the desired outcome is vague, so even if many performance improvements were made, it would be hard to say if this issue could be closed. I think more targeted perf issues that focus on getting some area of code to meet some performance goal would be better way forward.

[ara4n]

#4997 is related, but i'd suggest keeping this open - it's literally "if you scrub the window around to resize it, it is incredibly sluggish to rerender"

[ara4n]

i suspect that killing the remaining gemini scrollbars with fire would help a lot.

[ara4n]

killing the remaining gemini scrollbars with fire did help a lot.

I still think we should profile the rendering properly though, relative to the original react example - my hunch is that there's something about our heavy use of nested flexbox that means that we're working CSS harder than we need to be, and strategically removing flexbox in a few places might speed things up enormously.

[germain-gg]

It seems that horizontal resizing of Element is pretty intense

Resizing takes about 37ms with a pretty heavy layout operation being performed. This happens when being in an idle room. Anything else significant being dealt with at the same time is going to make the resizing experience even slower