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Nvidia DGX Spark

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51–60 of 222 posts

Re: Nvidia DGX Spark

#51
post #43

The RAM bandwidth is so slow on this that you can barely train or do inference or do anything on it. I think the only use case they have in mind for this is fine tuning pretrained models.

It's the same as Strix Halo and M4 Max that people are going gaga about, so either everyone is wrong or it's fine.

M4 max has more than double the bandwidth.

Strix Halo has the same and I agree it’s overrated.

Re: Nvidia DGX Spark

#52
post #11

It's a bit disingenuous to claim 1 PFLOPs without making clear that's for FP4 (with "structured sparsity"?)

If you scroll down a little and see the chip icon, where it says "NVIDIA GB10 Superchip " it also says "Experience up to 1 petaFLOP of AI performance at FP4 precision with the NVIDIA Grace Blackwell architecture." Further down, in the exploded view it says "Blackwell GPU 1PetaFLOP FP4 AI Compute" Then further down in the spec chart they get less specific again with "Tensor Performance^1 1 PFLOP" and "^1" says "1 Theo…

Even if that "sparsity feature" is that two or of every four adjacent values in your areay be zeros, and that performance halves if not doing this?

I think lots of children are going to be very disappointed running their blas benchmarks on Christmas morning and seeing barely tens of teraflops.

(For reference see how the still optimistic numbers are for the H200 when you use realistic datatypes.

https://nvdam.widen.net/s/nb5zzzsjdf/hpc-datasheet-sc23-h200... )

Re: Nvidia DGX Spark

#53

While a completely different price point, I have a Jetson Orin Nano. Some people forget the kernels are more or less set in stone for product like these. I could rebuild my own Jetpack kernel but it’s not that straight forward to update something like CUDA or any other module. Unless you’re a business where your product relies on this hardware, I find it hard to buy this for consumer applications.

Came in here to say the same thing. Have bought 3 Nvidia dev boards and never again as you quickly get left behind. You're then stuck compiling everything from scratch.

Re: Nvidia DGX Spark

#54

Earlier quoted context omitted.

They're abysmal compared to anything dedicated at any reasonable batch size because of both bandwidth and compute, not sure why you're wording this like it disagrees with what I said. I've run inference workloads on a GH200 which is an entire H100 attached to an ARM processor and the moment offloading is involved speeds tank to Mac Mini-like speeds, which is similarly mostly a toy when it comes to AI.

Again, prompt processing isn't the major problem here. It's bandwidth. 256GB/s bandwidth (maybe ~210 in real world) limits the tokens per second well before prompt processing. Not entirely sure how your ARM statement matters here. This is unified memory.

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Re: Nvidia DGX Spark

#56
Most people are missing the point. LLMs are not the be all end all of AI.

Even if you were to say memory bandwidth was the problem, there is no consumer grade GPU that can run any SoTA LLM, no matter what you'd have to settle for a more mediocre model.

Outside of LLMs, 256 GB/s is not as much of an issue and many people have dealt with less bandwidth for real world use cases.

Re: Nvidia DGX Spark

#57

FP4-sparse (TFLOPS) | Price | $/TF4s 5090: 3352 | 1999 | 0.60 Thor: 2070 | 3499 | 1.69 Spark: 1000 | 3999 | 4.00 ____________ FP8-dense (TFLOPS) | Price | $/TF8d (4090s have no FP4) 4090 : 661 | 1599 | 2.42 4090 Laptop: 343 | vary | - ____________ Geekbench 6 (compute score) | Price | $/100k 4090: 317800 | 1599 | 503 5090: 387800 | 1999 | 516 M4 Max: 180700 | 1999 | 1106 M3 Ultra: 259700 | 3999 | 1540 ____________ Ap…

You are doing god's work.

In fact you're also doing the work Nvidia should have done when they put together their (imho) ridiculously imprecise spec sheet.

Re: Nvidia DGX Spark

#58

I was considering getting an RTX 5090 to run inference on some LLM models, but now I’m wondering if it’s worth paying an extra $2K for this option instead

If you want to run small models fast get the 5090. If you want to run large models slow get the Spark. If you want to run small models slow get a used MI50. If you want to run large models fast get a lot more money.

Re: Nvidia DGX Spark

#59
post #32

Earlier quoted context omitted.

Perhaps they are referring to default GPU allocation that is 75% of the unified memory, but it is trivial to increase it.

The GPU memory allocation refers to how capacity is alloted, not bandwidth. Sounds like the same 256-bit/quad-channel 8000MHz lpddr5 you can get today with Strix Halo.

384GB is 75% of 512GB. The M3 Ultra bandwidth is over 800GB/s, though potentially less in practice.

Using an M3 Ultra I think the performance is pretty remarkable for inference and concerns about prompt processing being slow in particular are greatly exaggerated.

Maybe the advantage of the DGX Spark will be for training or fine tuning.

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