[Saucz]

I think the biggest change and most wanted "feature" is a smoother UI, (which is what really makes Android UI not as pleasant to work with as ios), and now that we got it with Butter, I'm wondering for those that know the actual programming guts, is it a true fix in the way Android handles the UI or is it a complicated added "fix" that is a workaround for the problem. I remember reading a while back that the way Android handles the UI was fundamentally flawed and the whole code would need to be rewritten to fix it which Google was not willing to do.

[dmmarck]

So far it has been, but only time will tell once the source is released and we've all had the chance to accumulate heavy data/cache buildup.

[ragnarokx]

Whatever they did, they did an amazing job. Stock is truly a pleasure to use.

[Patrick Schroedl]

Following up on what dmmarck said, I think that Project Butter lies somewhere in the middle. I think it's a major upgrade that would be both noticeable and appreciated even if the oft-perceived "Android lag" did not exist. However, there is something to be said for attacking the root cause of a probem rather than its symptoms, -- much in the same way that diagnostic and emergency medicine are typically approached.

I do see optimizations being made in Android with each major release that are increasing the efficiency of the UI. Consider the fact that until 4.0, the stock Android UI was not hardware-accelerated. Once this GPU rendering was introduced, the speed and fluidity of the UI increased by a very noticeable amount.

As long as Google continues this trend of adding performance enhancers such as hardware acceleration and Project Butter -- while recognizing that streamlined and efficient code is always important -- I think we'll be alright.

Edit: ragnarok is definitely right on that.

[LCW]

as an iphone user, I find Project Butter a major leap forward on Android to reduce/eliminate lag. the naysayers will deny it, but lag was a real thing on Android devices. very small but still perceptible. Between ICS and JB on my Nexus, there is a noticeable improvement, and makes the Nexus a pleasure to use. I'll even go so far as saying it's still a tiny bit behind iOS for response, but if Google keeps improving/optimizing this, they'll equal or surpass iOS in fluidity.

[quamdar]

This and the camera improvements are what excite me the most about Jellybean. I haven't heard much about the camera stuff yet though so I'm not sure what that is exactly.

[Shadowriver]

Project Butter is improvement to Android UI drawing procedures thanks to VSync. VSync is a signal telling the code that is about to refresh the display (display is independed from GPU and CPU and refreshes whatever hardware is do) allowing to sync code with refresh rate. Thing is before JB there was VSync but it was only used for any tethering purposes, VSync only make frame draw when VSync signal is up (display refresh) and new Frame is ready at time, if it's not ready in time it waits for next VSync to avoid displaying half made frame resulting the tether which is more visible glitch then then lag. In JB they implement VSync also in drawing UI process, instead of being triggered occusally by specific events it's now being triggered by VSync signal, they also used to litend touch input gethering code which was havier, now it gether input on VSync signal. They also used triple buffering so CPU don't wait for GPU to finish drawing frame if does not make in VSync signal (which is regular) start preparing new data for next frame using new extra 3rd buffer, so there it reduces possible lag cause by long process. It does magically remove lag complitly, only reduce it's possibility and if it happens it tries to reduce it's effect (triple buffer), application or other things still may cause it:

It been all explain in this session:



btw those 2 making the best sessions on IO imo, they adding lot of humor in to it making it fun to watch and less boring

[Saucz]

having watched the video, its good to know that they start by acknowledging that there is a problem