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We were wrong about GPUs

fly.io

81–90 of 604 posts

Re: We were wrong about GPUs

#81

I shelled out for a 4090 when they came out thinking it would be the key factor for running local llms. It turns out that anything worth running takes way more than 24GB VRAM. I would have been better off with 2+ 3090s and a custom power supply. It’s a pity because I thought it would be a great solution for coding and a home assistant, but performance and quality isn’t there yet for small models (afaik). Perhaps DIGI…

I started buying Macs with more memory, no regrets. An M4 Max with 64GB (in a laptop, no less!) runs most small models comfortably (but get 96GB or more if you really intend to use 70B models regularly). And when I'm not running LLMs, the memory is useful for other stuff.

Re: We were wrong about GPUs

#82
post #47

Earlier quoted context omitted.

> phone-home licensing dance every time a Fly Machine started To userspace Nvidia license server (a) in each host, (b) for entire Fly cloud, or (c) over WAN to Nvidia cloud?

IIRC, (a) and (c), which I think sort of implies (b)? Really what we'd have wanted to do would have been to give Fly Machines MIG slices. But to the best of my understanding, MIG is paravirtualized; it doesn't give you SR-IOV-style PCI addresses for the slices, but rather a reference Nvidia's userland libraries pass to the kernel driver, which is a dance you can't do across VM boundaries unless your hypervisor does i…

Hypothetical scenario for Nvidia licensing of fast-start microVMs:

1. Instead of blocking VM start for license validation, convert that step into non-blocking async submission of usage telemetry, allowing every VM to start instantly. For PoC purposes, Nvidia's existing stack could be binary patched to proxy the license request to a script that isn't blocking VM start, pending step 2 negotiation.

2. Reconcile aggregate vGPU usage telemetry from Nvidia Fly-wide license server (Step 1) with aggregate vGPU usage reports from Fly's orchestration/control plane, which already has that data for VM usage accounting. In theory, Fly orchestration has more awareness of vGPU guest workload context than Nvidia's VM-start gatekeeping license agent, so there might be mutual interest in trading instant VM start for async workload analytics.

Re: We were wrong about GPUs

#83
I have a timeline that I am still trying to work through but it goes like this :

2012 - moores law basically ends - nand gates do t get smaller just more cleverly wrapped. Single threaded execution more or less stops at 2 GHz and has remained there.

2012-2022 - no one notices single threaded is stalled because everything moves to VMs in the cloud - the excess parallel compute from each generation is just shared out in data centres

2022 - data centres realise there is no point buying the next generation of super chips with even more cores because you make massive capital investments but cannot shovel 10x or 100x processes in because Amdahls law means standard computing is not 100% parallel

2022 - but look, LLMs are 100% parallel hence we can invest capital once again

2024 - this is the bit that makes my noodle - wafer scale silicon. 900,000 cores with GBs SRAM - these monsters run Llama models 10x faster than A100s

We broke moores law and hardware just kept giving more parallel cores because that’s all they can do.

And now software needs to find how to use that power - because dammit, someone can run their code 1 million times faster than a competitor - god knows what that means but it’s got to mean something - but AI surely cannot be the only way to use 1M cores?

Re: We were wrong about GPUs

#84

> The biggest problem: developers don’t want GPUs. They don’t even want AI/ML models. They want LLMs. System engineers may have smart, fussy opinions on how to get their models loaded with CUDA, and what the best GPU is. But software developers don’t care about any of that. When a software developer shipping an app comes looking for a way for their app to deliver prompts to an LLM, you can’t just give them a GPU. I'm…

I'm not entirely certain. Or perhaps we're all part of both groups.

I want to understand LLMs. I want to understand my compiler, my gc, my type system, my distributed systems.

On the other hand, I don't really care about K8s or anything else, as long as I have something that works. Just let me `git push` and focus on making great things elsewhere.

Re: We were wrong about GPUs

#85
post #3

I spent a month setting up serverless endpoint for a custom model last year with Runpod. It was expensive and unreliable, in addition to long cold boot times. The product was unusable even as a prototype, to cover the costs, I'd have to raise money first. In a different product, I was given some Google Cloud credits, which unlocked me to put the product in front of customer. This one also needed GPU but not as expens…

Give https://modal.com a spin -- email me at deven [at] modal.com and happy to help you get set up

Re: We were wrong about GPUs

#86

> The biggest problem: developers don’t want GPUs. They don’t even want AI/ML models. They want LLMs. System engineers may have smart, fussy opinions on how to get their models loaded with CUDA, and what the best GPU is. But software developers don’t care about any of that. When a software developer shipping an app comes looking for a way for their app to deliver prompts to an LLM, you can’t just give them a GPU. I'm…

You described two points in an spectrum in which: One end is PaaS like Heroku, where you just git push. The other end is bare metal hosting. Every option you mentioned (VPS, Manages K8S, Self Hosted K8S, etc) they all fall somewhere between these two ends of the spectrum. If, a developer falls into any of these "groups" or has a preference/position on any of these solutions, they are just called juniors. Where you en…

This is news to us. Our primary DX is a CLI. One of our defining features is hardware isolation. To use us, you have to manage Dockerfiles. Have you had the experience of teaching hundreds of Heroku refugees how to maintain a Dockerfile? We have had that experience. Have you ever successfully explained the distinction between "automated" Postgres and "managed" Postgres? We have not.

You're not wrong that there's a PaaS/public-cloud dividing line, and that we're at an odd place between those two things. But I mean, no, it is not the case that our audience is strictly developers who do nothing low-level. I spent months of my life getting _UDP_ working for Fly apps!

Re: We were wrong about GPUs

#87

I have a timeline that I am still trying to work through but it goes like this : 2012 - moores law basically ends - nand gates do t get smaller just more cleverly wrapped. Single threaded execution more or less stops at 2 GHz and has remained there. 2012-2022 - no one notices single threaded is stalled because everything moves to VMs in the cloud - the excess parallel compute from each generation is just shared out i…

Plenty of non-IT applications use lots of cores, e.g. physics simulations, constraint solving, network simulation used to plan roads or electrical distribution, etc.

Re: We were wrong about GPUs

#89
post #47

Earlier quoted context omitted.

IIRC, (a) and (c), which I think sort of implies (b)? Really what we'd have wanted to do would have been to give Fly Machines MIG slices. But to the best of my understanding, MIG is paravirtualized; it doesn't give you SR-IOV-style PCI addresses for the slices, but rather a reference Nvidia's userland libraries pass to the kernel driver, which is a dance you can't do across VM boundaries unless your hypervisor does i…

Hypothetical scenario for Nvidia licensing of fast-start microVMs: 1. Instead of blocking VM start for license validation, convert that step into non-blocking async submission of usage telemetry, allowing every VM to start instantly. For PoC purposes, Nvidia's existing stack could be binary patched to proxy the license request to a script that isn't blocking VM start, pending step 2 negotiation. 2. Reconcile aggregat…

Sure. We also could have virtualized CUDA ourselves, used MIG on the host-side, and done a proxy PCI passthrough driver thing in Cloud Hypervisor. I think we could have gotten it to work. But it would have been a huge lift. I'm glad we didn't try.

Re: We were wrong about GPUs

#90

It's really a shame GPU slices aren't a thing -- a monthly cost of $1k for "a GPU" is just so far outside of what I could justify. I guess it's not terrible if I can batch-schedule a mega-gpu for an hour a day to catch up on tasks, but then I'm basically still looking at nearly $50/month. I don't know exactly what type of cloud offering would satisfy my needs, but what's funny is that attaching an AMD consumer GPU to…

GPU slices are absolutely a thing. Only supported on the enterprise GPUs tho and requires an additional paid Nvidia software license.
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