Re: Browser Latency "50ms" Target Discussion

One addendum that I forgot to add:

On Mon, Mar 26, 2018 at 5:53 PM, Mark Rejhon <> wrote:
> (C) Extra refresh rate
> If you have ever swiped on a 120Hz iPad, then you can clearly see the
> benefits of a 120Hz refresh rate.  But the Safari browser doesn't take
> advantage of that in javascript animations (just smoother for scrolling,
> not for javascript animations -- e.g. runs at only 60
> frames per second on a 120Hz iPad).  This means there's a little more input
> lag for animations.   But to Apple's credit, they chose a low-latency LCD
> display for their tablets, so they have a priority to save battery (lower
> power consumption) so that is probably their basis of limiting JavaScript
> logic to 60Hz, adding slight input lag to HTML games.  This is not
> noticeable for most users, but I can certainly (as an annoyed gamer) notice
> when something is being artificially limited to 60Hz, and the increase in
> latency from an artificial framerate limit.  But power management is
> extremely important, and the lag of the iPad browser is "good enough".

When I said that, I meant to say that 60fps@120Hz has less lag than
60fps@60Hz.  This is because of the faster-scanout effect (each frame being
scanned-out in 1/120sec -- e.g. refresh cycles appear faster).   It's not
as low-lag nor as smooth as as 120fps@120Hz.   But 60fps@120Hz is laggy
than 60fps@60Hz.  And requires the exact same amount of Javascript power
consumption.  So that was the Apple move.

Received on Monday, 26 March 2018 22:10:56 UTC