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An Update on Apple M1/M2 GPU Drivers

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Re: An Update on Apple M1/M2 GPU Drivers

#111

Post by porphyra »

wtallis wrote: post #87
jms55 wrote: post #84

Earlier quoted context omitted.

You're looking at years of careful artist and engineer work to get something that looks almost as good as pathtraced visuals. The fact that it's so good without any raytracing is a credit to the developers. Replacing all that effort with raytracing and having one unified lighting system would be a _major_ time saver, and allows much more dynamic lighting than was previously possible. So yeah some current games don't…

> Sure fully pathtraced graphics might not be 100% usable currently, but the fact that they're even 70% usable is amazing! Aside from Cyberpunk 2077 and a handful of ancient games with NVIDIA-sponsored remakes, what even offers fully path traced lighting as an option? The way it went for CP2077 makes your "70% usable" claim seem like quite an exaggeration: performance is only good if you have a current-generation GPU…

UE5 supports fully path traced lighting and Black Myth Wukong is a recent example.

Re: An Update on Apple M1/M2 GPU Drivers

#112

Post by jms55 »

wtallis wrote: post #87
jms55 wrote: post #84

Earlier quoted context omitted.

You're looking at years of careful artist and engineer work to get something that looks almost as good as pathtraced visuals. The fact that it's so good without any raytracing is a credit to the developers. Replacing all that effort with raytracing and having one unified lighting system would be a _major_ time saver, and allows much more dynamic lighting than was previously possible. So yeah some current games don't…

> Sure fully pathtraced graphics might not be 100% usable currently, but the fact that they're even 70% usable is amazing! Aside from Cyberpunk 2077 and a handful of ancient games with NVIDIA-sponsored remakes, what even offers fully path traced lighting as an option? The way it went for CP2077 makes your "70% usable" claim seem like quite an exaggeration: performance is only good if you have a current-generation GPU…

> performance is only good if you have a current-generation GPU that cost at least $1k

That's why I said games aren't currently designed with only pathtracing in mind, but in 3-5 years with faster hardware and better algorithms, we'll probably start to see it be more widespread. That's typically how graphics usually develop; something that's only for high end GPUs eventually becomes accessible to everyone. SSAO used to be considered extremely demanding, and now it's accessible to even the weakest phone GPU with good enough quality.

Again the fact that it's feasible at all, even if it requires a $1000 GPU, is amazing! 5 years ago real time path tracing would've been seen as impossible.

> The way it went for CP2077 makes your "70% usable" claim seem like quite an exaggeration

Based on the raw frame timing numbers and temporal stability, I don't think it is. RT GI is currently usually around ~4ms, which is at the upper edge of usable. However the temporal stability is usually the bigger issue - at current ray counts, with current algorithms, either noise or slow response times is an inevitable tradeoff. Hence, 70% usable. But with another few years of improvements, we'll probably get to the point where we can get it down to ~2.5ms with the current stability, or 4ms and much more stable. Which would be perfectly usable.

Re: An Update on Apple M1/M2 GPU Drivers

#113

Post by adastra22 »

talldayo wrote: post #83
madeofpalk wrote: post #66

Earlier quoted context omitted.

The same was true about 3D TVs. Also a gimmick.

3D TVs failed before they existed as a product category. You cannot encode enough information through stereoscopy to create a convincing or "realistic" 3D effect. The conditions for making it work have always been fickle and as 6DOF VR/AR is proving, it was never enough to be convincing anyways. Encoding two slightly different versions of a video and layering them on top of each other is a dirty hack. It is not a hol…

Thank you. This guy gets it.

Path tracing is the gold standard for computer graphics. It is a physically based rendering model that is based on how lighting actually works. There are degrees of path tracing of varying quality, but there is nothing else that is better from a visual quality and accuracy standpoint.

Your modern AAA title does a massive amount of impressive hacks to get rasterization into the uncanny valley, as rasterization has nothing to do with how photons work. That can all be thrown out and replaced with “model photons interacting with the scene” if the path tracing hardware was powerful enough. It’d be simpler and perfectly accurate. The end result would not live in the uncanny valley, but would be indistinguishable from reality.

Assuming the hardware was fast enough. But we’ll get there.

Re: An Update on Apple M1/M2 GPU Drivers

#114

Post by HeuristicsCG »

comex wrote: post #79
jsheard wrote: post #37

Earlier quoted context omitted.

They had limited uses and turned out to be incredibly hard to implement efficiently in hardware, so in practice it was nearly always faster to just keep using the proven techniques that GS was supposed to replace. http://www.joshbarczak.com/blog/?p=667

And yet one of the fancy new features being advertised in recent years (in multiple APIs including Metal) is support for mesh shaders – which seem to have a lot in common with geometry shaders, including the output ordering property that that post blames for geometry shaders’ bad performance. I’m not a graphics programmer myself, but this makes me suspect there’s more to the story.

if your hardware supports mesh shaders properly, it won't be very hard for it to also support these other features emulated in software (geometry shaders, tessellation, lines etc).

But mesh shaders are fairly new, will take a few years for the hardware and software to adapt.

Re: An Update on Apple M1/M2 GPU Drivers

#115

Post by [deleted] »

ferbivore wrote: post #62
dagmx wrote: post #56

Earlier quoted context omitted.

Other hardware vendors absolutely do the same. Geometry shaders are poor performers on several other vendors for precisely the same reason

At least some Qualcomm, Imagination and Broadcom GPUs support geometry shaders in hardware. Not entirely sure about Arm. To be fair, it could be the support isn't very good.

[deleted]

Re: An Update on Apple M1/M2 GPU Drivers

#116

Post by hilti »

almostgotcaught wrote: post #85
dtquad wrote: post #39

Earlier quoted context omitted.

The graphics pipeline in modern GPUs are mostly a thin low-level Vulkan/Metal-like layer on top of a massively parallel CUDA-like compute architecture. It's basically all emulated. One of the reasons GPU manufacturers are unwilling to open source their drivers is because a lot of their secret sauce actually happens in software in the drivers on top of the massively parallel CUDA-like compute architecture.

I didn't read the article and don't know about Apple but that's definitely not true for everyone. Source: see amdgpu built on top of HSA. EDIT: to be precise yes ofc every chip is a massively parallel array of compute units but CUDA has absolutely nothing to do with it and no not every company buries the functionality in the driver.

[flagged]

Re: An Update on Apple M1/M2 GPU Drivers

#118

Post by wtallis »

jms55 wrote: post #112
wtallis wrote: post #87

Earlier quoted context omitted.

> Sure fully pathtraced graphics might not be 100% usable currently, but the fact that they're even 70% usable is amazing! Aside from Cyberpunk 2077 and a handful of ancient games with NVIDIA-sponsored remakes, what even offers fully path traced lighting as an option? The way it went for CP2077 makes your "70% usable" claim seem like quite an exaggeration: performance is only good if you have a current-generation GPU…

> performance is only good if you have a current-generation GPU that cost at least $1k That's why I said games aren't currently designed with only pathtracing in mind, but in 3-5 years with faster hardware and better algorithms, we'll probably start to see it be more widespread. That's typically how graphics usually develop; something that's only for high end GPUs eventually becomes accessible to everyone. SSAO used…

> RT GI is currently usually around ~4ms, which is at the upper edge of usable. However the temporal stability is usually the bigger issue - at current ray counts, with current algorithms, either noise or slow response times is an inevitable tradeoff. Hence, 70% usable. But with another few years of improvements, we'll probably get to the point where we can get it down to ~2.5ms with the current stability, or 4ms and much more stable. Which would be perfectly usable.

Maybe you should be saying 70% feasible rather than 70% usable. And you seem to be very optimistic about what kind of improvements we can expect for affordable, low-power GPU hardware over a mere 3-5 years. I don't think algorithmic improvements to denoisers and upscalers can get us much further unless we're using very wrong image quality metrics to give their blurriness a passing grade. Two rays per pixel is simply never going to suffice.

Right now, an RTX 4090 ($1700+) runs at less than 50 fps at 2560x1440, unless you lie to yourself about resolution using an upscaler. So the best consumer GPU at the moment is about 70-80% of what's necessary to use path tracing and hit resolution and refresh rate targets typical of high-end gaming in 2012.

Having better-than-4090 performance trickle down to a more mainstream price point of $300-400 is going to take at least two more generations of GPU hardware improvements even with the most optimistic expectations for Moore's Law, and that's the minimum necessary to do path tracing well at a modest resolution on a game that will be approaching a decade old by then. It'll take another hardware generation for that level of performance to fit in the price and power budgets of consoles and laptops.

Re: An Update on Apple M1/M2 GPU Drivers

#119

Post by karunamurti »

hoherd wrote: post #61
recvonline wrote: post #58

Any link to the fact that the drivers are written in Rust?

https://asahilinux.org/2022/11/tales-of-the-m1-gpu/ > Since this was going to be the first Linux Rust GPU kernel driver, I had a lot of work ahead! Not only did I have to write the driver itself, but I also had to write the Rust abstractions for the Linux DRM graphics subsystem. While Rust can directly call into C functions, doing that doesn’t have any of Rust’s safety guarantees. So in order to use C code safely fro…

I particularly like line 1322 and 1344

Re: An Update on Apple M1/M2 GPU Drivers

#120

Post by I_AM_A_SMURF »

jjmarr wrote: post #104
scottlamb wrote: post #14

> tessellator.cl is the most unhinged file of my career ...so far. The presenter is only 23 apparently. Maybe I'm speaking only for myself here, but I think career unhingedness does not go down over time as much as one might hope. In all seriousness, she does really impressive work, so when she says this 2,000 lines of C++ is inscrutable, that gives one pause. Glad it's working nonetheless.

I didn't even know this until now. I looked at her resume and I can't grasp how she's been doing an undergraduate degree from 2019-2023, meaning that writing an entire GPU driver is the side project she made during her degree.

For gifted people undergraduate degrees are easy (unless you want to go through it really fast). Some people I know barely studied for their exams and spent all their time in research projects / their own thing.
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