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Comment by dtquad | Hacker News Reader

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.

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As a former insider, this is NOT remotely how I would describe reality.

I have signed NDAs and don't feel comfortable going into any detail, other than saying that there is a TON going on inside GPUs that is not "basically all emulated".

Maybe a tall ask, but have you considered writing down all your experiences into a book, and release it after all NDAs expire? I’d love to read more about low level hardware and the behind the scenes stuff involved. I’m sure you’ve got a lot of good stories.

> I’d love to read more about low level hardware and the behind the scenes stuff involved. I’m sure you’ve got a lot of good stories.

I don't know why you think there's anything resembling "good stories" (I don't even know what would constitute a good story - swash buckling adventures?). It's just grimy-ass runtime/driver/firmware code interfacing with hardware features/flaws.

Exactly right.

95% difficult, stressful and surprisingly tedious work

4% panic, despair, insecurities

1% friendly banter with very smart people

If I had to do it all over again, I wouldn't, even though it allowed me to retire early.

My experience to a T, down to the 1% friendly banter (because while there are lots of smart people working on hardware, almost none of them know how to banter lol).

NDAs don't generally have an expiration date. (As opposed to non-competes and non-solicitation agreements, which generally do.) An NDA typically ends only if the information in question becomes public, and then only for that particular information.

Nope in all accounts, I'm afraid.

But, in summary, it was grinding, grinding, and more grinding, with large dollops of impostor syndrome on top of it.

Met lots of nice smart people, but none were as impressive as the folks at NVidia. I was not worthy of being there.

This statement isn't true at all. There are tons of fixed function hardware units for graphics in GPUs in addition to compute cores: triangle rasterizers, texture units, raytracing units, blitters, copy engines, video codecs, etc. They interact with the shader/compute cores and it's getting more common that the shader core is driving the rasterizer etc than vice versa (mesh shaders and ray tracing for example).

Calling it "all emulated" is very very far from the truth.

You can independently verify this by digging into open source graphics drivers.

How is verifying against a worse performing, open source GPU driver any sort of verification that proprietary drivers do not do special things you wouldn’t expect?

Because it would reveal the lack of emulation in the open-source driver, demonstrating that there are specialized hardware blocks performing those functions.

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.

You know it’s not like Apple has a lot to lose in terms of market share if they opened even the specs of their hardware up to make folks like the Asahi team’s lives’ easier. What does Apple have in terms of the desktop market? 5%?

If anything working, fully baked desktop Linux working on ARM Mac hardware would drive sales and Apple would still get the profits. Besides their services are still mostly available too. Tux loving folks can subscribe to AppleTV, and music etc.

A lot of it is software, but not necessarily in the driver. Nouveau folks pretty much gave up and use NVidia's firmware blob going forward. While that's mostly due to NVidia not cooperating in making crucial capabilities of the GPU available to non-signed firmware blobs, the upside is that it will hopefully significantly reduce the effort connected with wiring up new hardware components on the GPU.

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