Attention Photoshop Gurus - GPU Acceleration - any significant real-world difference?

[slugg]

This was a tough thread to start. I wasn't sure if this thread belonged in Software for Windows (Photoshop is also for Mac), All Things Apple (Photoshop is also for Windows), here, or somewhere else. So I decided to start with the Video Cards and Graphics forum, since we're kinda-sorta talking about GPU acceleration.

So what I'd like to know, from Photoshop gurus, is whether or not GPU acceleration makes any real perceivable difference. Benchmarks and measurements is one thing, but I'm more interested in whether or not actual usability is noticeably improved with GPU acceleration. If it is improved, would you say that non-GPU-accelerated Photoshop is "good enough?"

In your replies, if you don't mind, could you tell me the kind of Photoshop work you do? Typical image sizes, number of layers, market (i.e. photograph touchups, architectural rendering, forensics, etc).

FAQ:

Q: Why are you asking about this?
A: This thread got me thinking about a massive void in free software. I have a background in digital image processing, and I've been looking for a pet project, so I'm looking into the feasibility of starting an open source, light weight Photoshop alternative. Skipping GPU acceleration would greatly make things easier. Now before you tell me "Photoshop is a massive application and you'll never be able to make a clone," keep in mind that I used the word alternative, not clone.

 

[taserbro]

I do textures, illustrations and general picture editing with sizes anywhere between gif animations and 10 megapixel+ 4k formats often up to 100 layers.

IMHO, no. Gpu acceleration isn't sine-qua-non. It's nice to have and some features like canvas free rotation and anti-aliasing at all zoom levels actually require it but aside from those, it's mainly cosmetic like the zoom and pan animations.

I use 4 different programs for all the things that they do better than one another and some don't use gpu acceleration at all yet feel way smoother than photoshop without gpu acceleration. Go figure...

 

[Cerb]

I'm no guru, just an IT guy, but frankly, most users don't care. It's useful for Adobe and their users, because sufficiently powerful GPUs to help out are now included with every new system, right in the CPU, and that there are consistently users of their programs that are pushing the limits of what hardware can do. Everyone I know using Photoshop are all over being ticky about peripherals, not the PC, so long as it's not a POS, and has enough RAM.

If you design your preview and rendering functions so they can be pluggable, you can work from there. For instance, since new computers mostly support AVX, that would offer plenty over SSE2, which is already well-suited, and then AVX2 more-so.

 

[slugg]

Okay, so basically, a CPU-only implementation will be good enough. Yay. I'll think about it... I want a pet project, but a Photoshop alternative is kinda huge. Still thinking - just gauging plausibility of this for the time being.

 

[gorobei]

it depends on what aspect of PS you are targeting.

-people manipulating large megapixel images (filters/color correction/hdr) may need the power of gpu accel just based on the number of pixels involved.
-graphic design, illustration, content creation probably not that much of a gpu need, but they would probably want good tablet and mutitouch interfaces.
-image manipulation (old photo restoration/healing tool/airbrushing) probably want selection tools.

targeting dedicated gpus might not necessarily yield much improvement but being able to use the igp of APUs might not hurt.

 

[beginner99]

I think you have no idea how complex such software is. I can assure you that it is just not possible to do create such a software as lone developer. Especially since usable alternatives exist and hence your solution must somehow be superior.

You sure wont be able to beat GIMP on functionality. Yes, it is kind of complex and the UI isn't great. But creating great UIs is a science in itself.

 

[robertoblake]

Because I do Photo Manipulation with 24MP DSLR images I have a bit of a different take on this. I have noticed performance gains from GPU Acceleration in Photoshop. If you are not doing complext Photo Manipulations with 20+ layers and multiple images and using tools like blur and liquify filters, etc. then you won't notice the difference for the most part. If you are doing high end Photoshop it can be a huge performance boon for you.

I do go into this in depth in a blog post I wrote for those shopping for a decent graphics card for Photoshop:

http://robertoblake.com/blog/2014/01/best-video-graphics-card-photoshop/

One of the main things people get wrong is that they need a "gaming" graphics card with the maximum amount of VRAM. This spec doesn't matter for Photoshop or for video Editing in Final Cut Pro or Premiere. Memory Interface Width, Bandwidth and Clock Speed are the important Specs, that and the number of CUDA/Streaming Cores.

 

[robertoblake]

I think you have no idea how complex such software is. I can assure you that it is just not possible to do create such a software as lone developer. Especially since usable alternatives exist and hence your solution must somehow be superior.

You sure wont be able to beat GIMP on functionality. Yes, it is kind of complex and the UI isn't great. But creating great UIs is a science in itself.

I couldn't agree more. People underestimate this to an unbelievable degree.