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Liquid Glass? That's what your M4 CPU is for

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Re: Liquid Glass? That's what your M4 CPU is for

#51

Post by JKCalhoun »

fainpul wrote: post #29
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

If that's so, can't he explain it ELI5 style instead of calling people idiots? I have a hard time believing that the GPU is somehow magically energy efficient, so that computing this glass stuff uses barely any energy (talking about battery drain here, not "unused cycles").

My generous interpretation is that he means the GPU is magically energy efficient compared to the CPU. I wouldn't dispute that.

But Apple went down that xPU-taxing path a long time ago when they added the blur to views beneath other views (I don't remember what that was called).

Re: Liquid Glass? That's what your M4 CPU is for

#52

Post by arghwhat »

artemisart wrote: post #42
arghwhat wrote: post #24

Earlier quoted context omitted.

Blur is expensive because it propagates damage and has to wait for all previous rendering to be complete. When one pixel changes underneath a blur the entire blurred area needs to be redrawn, meaning that all elements on top needs to be redrawn. As the blur cannot render before the underlay is finished, the graphics pipeline is stalled. Fancy blur look past the area immediately underneath to more accurately lens effe…

No, you never compute individual pixels because you never need to, and it's always faster to it in bulk (vectorization, memory access...) and so over an area you take the same number of pixels as input (or a little bit more with padding) and the blur will only increase significantly the compute.

You misunderstood, this is not about computing individual pixels but only selective rerendering graphical elements which have been changed, and in turn figuring out the total area of change. This propagates through the entire stack to let the GPU scanout hardware know which tiles have changed, and allow partial panel self refresh updates (depending on hardware).

Rendering is still done in bulk for the changed areas, avoiding rendering expensive elements (e.g., transformed video buffers, deeply layered effects, expensive shaders). It's a fundamental part of most UI frameworks.

Re: Liquid Glass? That's what your M4 CPU is for

#53

Post by rickdeckard »

depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

Depends on whether "expensive" refers to

a.) Compute-cycles: Some added passes to apply additional shading on top of the completed render, or

b.) Power-consumption: Some added delay in putting components to sleep (reducing CPU/GPU-clock) on every screen update.

Deferred sleep for a portable, battery-powered device because of a longer UI-rendering pipeline can easily add up over time.

--

I'd be quite interested to see some technical analysis on this (although more out of technical curiosity than the assumption that there is something huge to be uncovered here...).

There's also the aspect of iOS prioritizing GUI-rendering over other processing to maintain touch-responsiveness, fluidity, etc. Spending more xPU-time on the GUI potentially means less/later availability for other processes.

For sure non-native apps trying to emulate this look (i.e. Flutter) will create a significantly higher impact on the power-profile of a device than a native app.

Re: Liquid Glass? That's what your M4 CPU is for

#54

Post by alluro2 »

mort96 wrote: post #44
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

I'm inclined to believe what I have experienced. I have never before experienced my 2020 iPad Pro to be remotely slow. I use it for some web browsing and YouTube viewing, so I really don't need a lot of computing power. Now that I'm running the iOS 26 beta, I frequently feel animations going slowly or hitching. It's not terrible, but for the first time, I have the feeling that my experience using my iPad would be not…

Sounds like it's working exactly as intended.

Re: Liquid Glass? That's what your M4 CPU is for

#56

Post by [deleted] »

fainpul wrote: post #29
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

If that's so, can't he explain it ELI5 style instead of calling people idiots? I have a hard time believing that the GPU is somehow magically energy efficient, so that computing this glass stuff uses barely any energy (talking about battery drain here, not "unused cycles").

[deleted]

Re: Liquid Glass? That's what your M4 CPU is for

#58

Post by DougBTX »

fainpul wrote: post #29
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

If that's so, can't he explain it ELI5 style instead of calling people idiots? I have a hard time believing that the GPU is somehow magically energy efficient, so that computing this glass stuff uses barely any energy (talking about battery drain here, not "unused cycles").

Here's an attempt at that: The GPU is responsible for blending layers of the interface together. Liquid glass adds a distortion effect on top of the effects currently used, so that when the GPU combines layers, it takes values from (x + n, y + m) rather than just (x, y). Energy efficiency depends on how much data is read and written, but a distortion only changes _which_ values are read, not how many.

Re: Liquid Glass? That's what your M4 CPU is for

#59

Post by andai »

mort96 wrote: post #44
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

I'm inclined to believe what I have experienced. I have never before experienced my 2020 iPad Pro to be remotely slow. I use it for some web browsing and YouTube viewing, so I really don't need a lot of computing power. Now that I'm running the iOS 26 beta, I frequently feel animations going slowly or hitching. It's not terrible, but for the first time, I have the feeling that my experience using my iPad would be not…

I experience this basically any time I upgrade my phone OS. There's never anything new that makes me happy, it's always either they removed something I used, made something uglier, and always it's 2-3x slower than it used to be.

Same thing with Windows. If they just stopped touching it 20 years ago, it would be 50x more responsive now.

Re: Liquid Glass? That's what your M4 CPU is for

#60

Post by zuhsetaqi »

mort96 wrote: post #44
depr wrote: post #11

I'm inclined to believe what 'mitchellh wrote: "The Liquid Glass effects are not expensive and anyone claiming they are has no idea how modern GPUs and animation work. Anyone saying it is is either just parroting or is an idiot." https://x.com/mitchellh/status/1933314816472723728

I'm inclined to believe what I have experienced. I have never before experienced my 2020 iPad Pro to be remotely slow. I use it for some web browsing and YouTube viewing, so I really don't need a lot of computing power. Now that I'm running the iOS 26 beta, I frequently feel animations going slowly or hitching. It's not terrible, but for the first time, I have the feeling that my experience using my iPad would be not…

Beta versions are always slow and sluggish. Just install the latest beta of iPadOS 18. It will be sluggish. The reason is that in beta versions there is a lot of logging and reporting running in the background which can not be disabled.
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