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Hacked Nvidia 4090 GPU driver to enable P2P

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Re: Hacked Nvidia 4090 GPU driver to enable P2P

#161

What stops nvidia from making sure this stops working in future driver releases?

The law, hopefully.

Beeper mini only worked with iMessage for a few days before Apple killed it. A few months later the DOJ sued Apple. Hacks like this show us the world we could be living in, a world which can be hard to envision otherwise. If we want to actually live in that world, we have to fight for it (and protect the hackers besides).

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#162
post #80

Incredible! I'd been wondering if this was possible. Now the only thing standing in the way of my 4x4090 rig for local LLMs is finding time to build it. With tensor parallelism, this will be both massively cheaper and faster for inference than a H100 SXM. I still don't understand why they went with 6 GPUs for the tinybox. Many things will only function well with 4 or 8 GPUs. It seems like the worst of both worlds now…

I don't think P2P is very relevant for inference. It's important for training. Inference can just be sharded across GPUs without sharing memory between them directly.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#163
post #80

Incredible! I'd been wondering if this was possible. Now the only thing standing in the way of my 4x4090 rig for local LLMs is finding time to build it. With tensor parallelism, this will be both massively cheaper and faster for inference than a H100 SXM. I still don't understand why they went with 6 GPUs for the tinybox. Many things will only function well with 4 or 8 GPUs. It seems like the worst of both worlds now…

I don't think P2P is very relevant for inference. It's important for training. Inference can just be sharded across GPUs without sharing memory between them directly.

It can make a difference when using tensor parallelism to run small batch sizes. Not a huge difference like training because we don't need to update all weights, but still a noticeable one. In the current inference engines there are some allreduce steps that are implemented using nccl.

Also, paged KV cache is usually spread across GPUs.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#164

Earlier quoted context omitted.

I’ve got a few 4090s that I’m planning on doing this with. Would appreciate even the smallest directional tip you can provide on splitting the model that you believe is likely to work.

The split is done automatically by the inference engine if you enable tensor parallelism. TensorRT-LLM, vLLM and aphrodite-engine can all do this out of the box. The main thing is just that you need either 4 or 8 GPUs for it to work on current models.

[deleted]

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#165

Earlier quoted context omitted.

Yes, but he spent several years in self-driving cars ( https://comma.ai ), which while interesting is also a space that a lot of players are in, so it's not the same as seeing him back to doing stuff that's a little more out there, especially as pertains to IP.

Did he abandon this effort? That would be pretty sad bec he was approaching the problem from a very different perspective.

It's still a company, still making and selling products, and I think he's still pretty heavily involved in it.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#166
post #80

Incredible! I'd been wondering if this was possible. Now the only thing standing in the way of my 4x4090 rig for local LLMs is finding time to build it. With tensor parallelism, this will be both massively cheaper and faster for inference than a H100 SXM. I still don't understand why they went with 6 GPUs for the tinybox. Many things will only function well with 4 or 8 GPUs. It seems like the worst of both worlds now…

A macbook is cheaper though

So is a TI-89.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#167

Earlier quoted context omitted.

> Toy-level, not-yet-harmful AIs on the other hand are real. A computer that can cause harm is much different than the absurd claims that I am disagreeing with. The extraordinary claims that are equivalent to saying that the imperious curse exists would be the magic computers that create diamond nanobots and mind control humans. > that more powerful AIs will exist in the future Bad argument. Non safe Boxes exist in r…

Instead of gesturing at flawed analogies, let's return to the actual issue at hand. Do you think that agents more intelligent than humans are impossible or at least extremely unlikely to come into existence in the future? Or that such super-human intelligent agents are unlikely to have goals that are dangerous to humans? Or that they would be incapable of pursuing such goals? Also, it seems obvious that the standard…

[deleted]

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#168

Earlier quoted context omitted.

Interesting... 1 Zen 4 EPYC CPU yields a maximum of 128 PCIE lanes so it wouldn't be possible to put 8 full fat GPUs on while maintaining some lanes for storage and networking. Same deal with Threadripper Pro.

It should be possible with onboard PCIe switches. You probably don't need the networking or storage to be all that fast while running the job, so it can dedicate almost all of the bandwidth to the GPU. I don't know if there are boards that implement this, though, I'm only looking at systems with 4x GPUs currently. Even just plugging in a 5kW GPU server in my apartment would be a bit of a challenge. With 4x 4090, the…

8 GPUs x 16 PCIe lanes each = 128 lanes already.

That’s the limit of single CPU platforms.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#169
post #24

Glad to see that geohot is back being geohot, first by dropping a local DoS for AMD cards, then this. Much more interesting :p

Is this the same guy that hacked the PS3?

He has a very checkered history with "hacking" things.

He tends to build heavily on the work of others, then use it to shamelessly self-promote, often to the massive detriment of the original authors. His PS3 work was based almost completely on a presentation given by fail0verflow at CCC. His subsequent self-promotion grandstanding world tour led to Sony suing both him and fail0verflow, an outcome they were specifically trying to avoid: https://news.ycombinator.com/item?id=25679907

In iPhone land, he decided to parade around a variety of leaked documentation, endangering the original sources and leading to a fragmentation in the early iPhone hacking scene, which he then again exploited to build on the work of others for his own self-promotion: https://news.ycombinator.com/item?id=39667273

There's no denying that geohotz is a skilled reverse engineer, but it's always bothersome to see him put onto a pedestal in this way.

Re: Hacked Nvidia 4090 GPU driver to enable P2P

#170
post #10

If we end up with a compute governance model of AI control [1], this sort of thing could get your door kicked in by the CEA (Compute Enforcement Agency). [1] https://podcasts.apple.com/us/podcast/ai-safety-fundamentals...

If it could be another acronym than the renowned french Atomic Energy Commission, the CEA.
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