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Scrolling through layers in photoshop doesn't necessarily just scroll a list though, it's also actively selecting the content of those layers... which can be very complex (I didn't watch the demo so I'm not entirely sure of the specific scrolling context).

You're dealing with filters, transparencies, hand-drawn paths, masking, linked files, embedded files — there's a wide realm of potential data and complexity.

If you want to test the mettle of a computer, try opening a large Photoshop file and doing anything in it.

People who use Photoshop regularly totally understand the validity of that quick demo.

If you want to test the mettle of a computer, try opening a large Photoshop file and doing anything in it.

This, right here, is why it's an indictment of the software industry. It SHOULDN'T be impressive that Photoshop doesn't lag. When she said that line, the entire audience should have shrugged and said to themselves "Of course you can zoom into an image in Photoshop. It's 2018. What's the big deal?"

I don't know enough about software to contest that statement, but I suspect you could be underestimating the the complexity of what Photoshop does.

We're also talking about multi-gig files. Outside of media the occurrence of an individual application file this large is pretty small. It's not like you can reliably play a 4K video file on many entry-level machines either.

In a similar vein, I would argue that it's a better indictment of the industry that I sometimes have to close Chrome because it's hogging more resources than Photoshop.

I think the obvious point is that whilst what photoshop does is very complex and computationally intensive, it's not new. The vast majority of the functionality in an average photoshop file is the same as was in the product 15 years ago. We really have reached the point of diminishing returns. And doing those tasks 15 years ago wasn't slow, so it's questionable why photoshop hasn't scaled in speed with the hardware.

I know you're trying to make the point that most software is bloated/slow/etc. but this is not the example to use for that point. Things don't just get faster because it's current year. The size of photos has increased by orders of magnitude since Photoshop debuted, the size of screens has increased, and the capabilities of the program have increased. In Photoshop, it is not only plausible but commonplace to have multiple 50MB files visible simultaneously, some raster, some vector, some text or shape. It's also worth considering that Photoshop only really uses 2 cores at maximum anyway.

> It's also worth considering that Photoshop only really uses 2 cores at maximum anyway.

Seriously? I think this is more confirming that the person you replied to is right. Unless there is some reason that I can think of that only using 2 cores is a good thing?

Answering this question means you have to understand a bit about how computers work. More cores doesn't automatically translate to faster performance. Photoshop is lightly threaded for most operations.

A cursory search brought up this link, but you should read up on threads and the difference between CPUs and GPUs:

https://macperformanceguide.com/blog/2017/20171223_2311-why-...

What would you do with more CPU cores? One for the UI; one for CPU-only filters (if there are such a thing) and various other background workers like network downloads.

Everything else—the rendering, scaling, compositing, etc.—runs on the GPU, not the CPU, where it uses hundreds of cores. Y’know, like a 3D game.

And, like a 3D game, it’s still slow, because it’s doing something genuinely hard and your powerful GPU still isn’t powerful enough.

These are things that are processed better by a smaller number of more powerful cores than a larger quantity of cores.

Multiple cores are really good at handling a lot of smaller processes. Photoshop just has a couple really heavy individual processes.

Not “orders of magnitude”, no.

Demo was 12,000 x 12,000 pixels, 2 orders of magnitude would be pictures of 120 x 120 pixels.

We did more with Photoshop in the past than 128px icons.

12000 x 12000 = 1.44 * 10^8 pixels.

120 x 120 = 1.44 * 10^4 pixels.

4 orders of magnitude. And in addition to that, the RAW sensor information from the camera has given each pixel more 'depth'. Often times, each color is 12bit (36bit per pixel). There's more to each pixel than what's displayed on the screen: its not just a JPG you're viewing.

Why does Photoshop use only 2 cores at maximum?

The demo file shown at the event was 12000x12000, 127 layers. It was 3GB on disk, 5GB fully loaded into memory. Double-tap to zoom was happening at 120Hz, fully animated, to anywhere within the document.

I realize I'm biased, but on such a machine, the observed performance is anything but rudimentary.

It's not impressive if it's not doing it with ideal sharpness in real-time, which it wasn't.

Tiled zooming into arbitrarily large images is otherwise rather easy to do. Go plop the largest image you can find onto your nearest Android phone and it'll zoom & pan that image at 60fps with nary a stutter or issue. It will take a while for it to re-snap the sharpness as you zoom in, though, but so was the iPad Pro. How fast it was re-decoding at the new scale factor & crop is the interesting question, but one which wasn't covered.

Otherwise we're just talking the same basic tech behind gigapixel viewers. Which isn't interesting or significant in the slightest, and has been used on mobile for years and years and years.

> It's not impressive if it's not doing it with ideal sharpness in real-time, which it wasn't.

Do you have evidence backing up this claim?

> Go plop the largest image you can find onto your nearest Android phone and it'll zoom & pan that image at 60fps with nary a stutter or issue

I've never seen an Android device composite, pan, and zoom a multi-layer gigapixel image with the same performance I saw today. If you have a video you could share, I'd be interested to see it.

> It will take a while for it to re-snap the sharpness as you zoom in

To let you in a bit, Photoshop was doing the recomposition of the destination region in real-time. And it's not just a single layer that's on display there, but hundreds, composited together while the user zooms in and out on varying regions of the document.

I've once tried using different devices to render a down-scaled version the full-stitch of XKCD Click and Drag. No device I've tried can allow me to zoom and pan at 60fps. On my Mac, there is some noticeable latency when quickly zooming or panning, and it's definitely not 60fps. I have no reason to believe any old Android phone will do it better.

Now I don't doubt that an image viewer specially optimized for zooming and panning huge images like this can do it at 60fps. The typical image viewer likely does not.

You think a many-layered PSD file is comparable to zooming a single image?

That's like wondering why the source + instrumented dev environment uses so much more resources than its compiled, optimized binary.

What a weird confusion to see on HN.

Of course, because it is. It's going to do a tiled render, likely at powers of 2, and all the heavy many-layer PSD stuff is completely asynchronous from the actual panning & zooming.

Or are you so naive you think that anything of significance is happening on or blocking the UI thread such that merely showing "smoothness" in any way reflects anything about the device's performance at actually doing the photoshop work?

If you're just viewing it, the pre-raster is only ~500MB, which easily fits in memory and zoom and pan are free. Pretty much any 2GB+ device would do that. Now editing and changing visibility and filters and such are much more complicated, but a view demo is not really a workout for anything vaguely done correctly.

Then write a competitor to Photoshop that performs better, since doing so is not a big deal.

I think the app was applying filters to a large image on the fly as she was doing that, so it’s not unimpressive.

There are plenty of times when I say "this software is bloated, inefficient, and should be snappy".

Scrolling through a 3 GB 157-layer 12000x12000 image is not one of those times.

It was a 3gig PSD file. That is pretty impressive.

No! It's not! Not in 2018! You only think it's impressive because you're used to UI's being total fucking shit! That's why it's an indictment of the software industry!

I'm not saying it's not hard: it is hard. Programming is hard. Making sure you're not occupying the UI thread for more than 16 milliseconds per frame is sometimes a challenge. You have to use all sorts of scary stuff like "concurrency" and "threads" and "GPUs". But it's 2018: non-laggy UI's should be the baseline everywhere, for everything.

I'm glad somebody else feels this way, when my Amiga 1200 runs smoother than most modern computers you know something has gone horribly wrong.

Yes, my washing machine also runs completely smoothly. One turn of the dial and it has selected the correct program without any lag!

Apples and Oranges.

I just had my whole Mac lock up after beginning the extraction of a xip archive. It is absolutely unacceptable for the UI to stop responding no matter how much load my computer is under.

My Amiga never did this because the whole user interface was interrupt driven, it wasn't possible for any of the bloated trash running to deem itself more important.

Yes, I edit 12000x12000 Photoshop images in real-time on my TRS-80 Model 4 every day. Kids these days.

How big are the images you view on it?

Again, the demo was performing some very impressive operations on the images in real time, not just making sure the UI was responsive.

Sounds like you just don't understand the challenges of what was demonstrated rather than a lamentation of modern software. Like reading kids on /r/gaming complain that a game doesn't have unlimited draw distance yet have no clue why there's a limitation.

What exactly should people be impressed by, if not hard things done well?

I feel you are not wrong. But I have no hope that quality and performance will be demanded any time soon, considering how vehemently Javascript desktop software is defended here with terms like 'time to market', 'users have spoken' etc

Was this during the presentation where they were dealing with a huge photoshop file?

Yes, I'm critical of the presenters that Apple chooses often but I thought that comment made sense in the context, especially coming from someone that was likely more an Artist than a technologist.

Maybe I'm being harsh, but I really don't think that it should be impressive that, on a device of this power, you can zoom in and out of a photoshop file without the UI lagging. Note, btw, that the pixels aren't updating in real time, it takes a little bit for the higher resolution to pop in when she zooms in (unless they're recently in cache). She's literally talking about not having the UI lag. This shouldn't be an applause line, this should be basic functionality in 2018.

It's a 12GB file with literally thousands of image filters being applied in realtime on a tablet. It's not about the UI it's about the image selection and realtime filters on a GIANT composite image. That's one hell of a lot of processing happening.

Yeah, if you’ve never pushed Photoshop and think it’s just a photo editing software then it’s understandable that you’d feel this way.

This exactly. People don't seem to grasp just how powerful Photoshop is, and just what kind of power you need to utilize it.

I’d assume so. I don’t recall any other mention of scrolling performance.

UI speed has always been a feature. At one point in Mac OS X, finder window resizing was very laggy.

I think Steve even did a keynote demo of fluid finder window resizing during 10.2 release.

reference: https://macosx.com/threads/why-is-window-resizing-so-slow-st...

Shouldn’t you be more specific and say an indictment of Photoshop or Adobe?

Perhaps they have a lot they can optimize but the levels of layers, masking, opacity, blending or whatever is complex.

There’s a lot to be said about reduced efficiencies with the layers of languages and abstractions we use today but I’m not sure photoshop is the best example to try and torch the whole industry.