[Rusky]

> Actually that's not correct. Vulkan was explicitly designed to be an efficient and high-performance API. As it stands, even as a newborn API, it's the BEST available for 3D rendering on all platforms that support it, unofficial or not.

Just because it was designed to be high-performance doesn't mean it automatically wins on platform support and implementation quality. Direct3D 12 is at the same level as Vulkan, and I see no reason for the trend of D3D being higher quality than GL to end with Vulkan.

[ioquatix]

Those are pretty subjective assertions. Do you have any evidence to back that up?

[om2]

Do you have any evidence for your claim that Vulkan is best? Metal and D3D 12 are also low-level APIs designed for performance. I've seen no evidence that Vulkan is better on platforms where there are drivers for two different APIs.

[Zandikar]

I think we've all gone a bit off the rails here.

Although you and those you've been discussing this with can't agree on which API is better, there's plenty of evidence that Vulcan, Metal and Dx are all quite good. Why then would we introduce yet another "standard" from scratch, as opposed to working to implement one of the existing ones better across platforms (if the desire is truly to build a universal gfx api)?

[om2]

Making a new standard is inevitable. That's not really a choice.

Even if the web platform directly replicated one of the existing APIs, you still have to explain how it binds to JavaScript, as well as memory and GPU resource management details. So bringing a modern graphics API to the web will inevitably create a new standard.

The question then is whether to try to clone one of the native-level APIs, or make something that works on each of the top 3. We think working on all of them is better than tying ourselves to just one.

[shmerl]

> The question then is whether to try to clone one of the native-level APIs, or make something that works on each of the top 3. We think working on all of them is better than tying ourselves to just one.

Besides this approach being supportive of lock-in (of underlying closed APIs like Metal and DX), which is more than questionable, more importantly, what shading language should this Web API use for example?

[simonh]

Tying the implementation to a single underlying API is just another kind of lock-in. You can be locked in to an open standard just as much as a proprietary one. Suppose this had been proposed 5 years ago and been tied deeply into OpenGL? In the world of today, that would pretty much make it a dead end. It's just not the job of a standard like this to pick and choose winners at a different level of abstraction.

[ioquatix]

When you look at the amount of effort that's gone into SPIR-V you'll only have one conclusion to this question.

[bobajeff]

This brings another question. Would it be better given the likely use cases for WebGPU to be designed as a WebAssembly only API?

[om2]

WebAssembly doesn't currently have a way to expose APIs to it directly. It only has an interface to call JavaScript.

Maybe that will change, but blocking on a major new WebAssembly feature did not seem wise.

[staticautomatic]

Why is making a new standard inevitable?

[ioquatix]

Well, I guess you know all this but you've asked me to elaborate. So, in terms of compatibility you have:

DX12: Windows only. Metal: macOS/iOS only. Vulkan: cross-platform and cross-vendor. Windows 7/8/10, Android, Linux, MoltenVK supports iOS/macOS with a wrapper. That's a big win for Vulkan IMHO. Valve also agrees with this assertion.

In terms of performance, I don't think Metal is even a contender, given how bad macOS hardware is compared to Wintel. w.r.t. Vulkan vs DX, from what I've seen it's pretty close, with Vulkan usually coming out ahead by a few performance points but of course it depends a lot on the implementation when it's at that level. Vulkan has been shown to be systematically better than OpenGL.

[MrScruff]

It makes no sense to judge the quality of an API by the power of the available hardware it might be running on. The discussion is not about what platform will run VR the best.

In addition, Apple will be rightly considering iOS when evaluating options for web technologies, not the increasingly small section of the planet running Nvidia and AMD hardware on Windows.

[ioquatix]

> It makes no sense to judge the quality of an API by the power of the available hardware it might be running on.

I didn't make any such judgement or even mention VR a single time!

But, looking at the points you've raised, I can say with confidence that Vulkan has been designed, taking into considering these issues.

Vulkan has been carefully engineered from the ground up not to alienate tile-based renderer hardware. So, it's just as suitable for mobile GPUs as desktop GPUs. https://www.imgtec.com/blog/tiling-positive-or-how-vulkan-ma...

As such, it's already supported by many mobile GPU hardware vendors.

> In addition, Apple will be rightly considering iOS when evaluating options for web technologies, not the increasingly small section of the planet running Nvidia and AMD hardware on Windows.

The GPU in the iPhone 7 uses a custom version of the PowerVR GT7600 GPU. While this is purely speculation, PowerVR does support Vulkan in their other offerings, so it's not that much of a stretch to assume that the hardware is at least capable of it.

NVidia, AMD and Intel power all of Apple's desktop graphics, in addition, they collectively power almost all of Windows and Linux setups too (excepting other mobile and SFF computers)

[Angostura]

You did make such a judgement- you wrote:

> In terms of performance, I don't think Metal is even a contender, given how bad macOS hardware is compared to Wintel.

[foobiekr]

It does, though.

Many times bottlenecks and missteps are not really visible until you can see how your decisions and assumptions encounter reality especially when every other chokepoiht has been removed.

Unless they did their development on Windows or on hardware that has never shipped, Apple isn't really in the position to have evaluated how well Metal works in reality.

I would add that the awkwardness of some "good" API designs is often not revealed until much later (and this is doubly true in the graphics space where there is ample evidence of API choices revealing themselves to be stuck with what turned out to be bad choices some times later).

[Rusky]

There's nothing subjective about it. Take a look at the APIs, they operate at the same level and are designed around the same principles.

As for past driver quality, ask a graphics developer doing anything more complicated than a toy weekend project. OpenGL drivers are inconsistent and buggy.

[ioquatix]

> Just because it was designed to be high-performance doesn't mean it automatically wins on platform support and implementation quality.

I never asserted that. I didn't even qualify what I meant by "BEST". But, let's evaluate the qualities you mention:

> platform support

Vulkan objectively wins here, supporting Windows 7/8/10, Linux, macOS/iOS with a wrapper, Android, etc. Intel has unofficial drivers for their x86 iGPU. Qualcomm recently announced hardware support, along with ARM.

> implementation quality

Vulkan is developed as an open specification, and has a full conformance test for implementations (https://www.khronos.org/vulkan/adopters/). Many aspects of Vulkan are available on GitHub and you can submit PRs. In my experience, drivers on Linux are very good and there are frequent updates. We currently deploy Vulkan at scale in production and haven't had a single issue with reliability.

In addition, the Vulkan validation layers assist with development because they check almost all API invariants and log incorrect usage. This helps to develop programs that work correctly according to the specs.

So, from the driver stack to the client software, Vulkan, IMHO, has a quality and well thought out implementation.

In comparison to DX12, which is developed behind closed doors, we don't know the implementation quality.

I personally haven't heard about any major bugs in Vulkan drivers, but I have seen quite few DX12 demos plagued by bugs. That's my subjective opinion though.

> Direct3D 12 is at the same level as Vulkan

Vulkan is better than DX12 in terms of openness, conformance testing, development tools, platform support, etc. Performance is about the same.

Even Valve agrees: http://www.kitguru.net/components/graphic-cards/anton-shilov...

> OpenGL drivers are inconsistent and buggy.

Agreed :)

[hifigi]

I make no argument against what you've said except you used Valve as an "appeal to authority", when they have a vested interest in promoting Vulkan (since SteamOS is based on Linux). So of course they will be persuading developers to use Vulkan over DX12, because it broadens the domain of users who can buy an individual title on Steam.

[ioquatix]

If you look up the endorsement by Valve, it's not just a straight up "Use Vulkan" but a well reasoned set of arguments and case studies by people with a lot of experience. So, this is not an "appeal to authority", but a reference to an existing body of research which supports my assertions.

[Rusky]

By "platform support," I was not referring to the number of platforms supported by the API, but the quality of support for the API provided by the platform(s). Vulkan objectively loses to D3D and Metal here.

We absolutely know the implementation quality of D3D- you don't have to see the source to see its performance, its stability, or its adherence to the spec. On the whole, it's far more consistent and stable than OpenGL and there is no reason to believe Vulkan will change any of that as it uses the same process for specification, development, and deployment.

[ioquatix]

The Vulkan development process is very different from OpenGL. It's a significant improvement so it's not fair to make this judgement. There is significant evidence: The quality of the API, the number of platforms supported within the first 12 months of publication, the availability of source code and documentation on GitHub (including allowing contributions). These are all things which are far better than the equivalent DX model, and also, in comparison, OpenGL.

[Rusky]

None of that directly impacts Vulkan driver implementation quality (which is not open source at all).