A local AI box isn’t there to replace the cloud for large-scale training. It exists for three specific things: keeping sensitive data off someone else’s servers, avoiding metered API costs when you’re iterating hundreds of times a day and getting a fixed, predictable machine you fully control instead of a shared, rate-limited one. Cloud GPUs still win for large training runs and burst capacity. A local box wins for prototyping, fine-tuning smaller models and running inference on data you’re not allowed to send anywhere else. That’s the tradeoff, and it decides which of these three ecosystems actually fits your work.

NVIDIA, AMD and Apple are all shipping new local AI hardware on a near-constant cycle right now. Let’s look at which machine actually makes sense for you.

NVIDIA: the safe, expensive default

The NVIDIA DGX Spark pairs 128GB of unified memory with a Grace Blackwell GB10 chip built around CUDA, which is still the deepest, most battle tested software ecosystem in AI. Existing PyTorch code, TensorRT and cuDNN pipelines run on it without modification, which is not something you can say about the other two options yet.

The advantage is that nothing needs to be rewritten or reverse engineered. If your team already builds on CUDA, this is the lowest friction way to bring that work local. The drawback is memory bandwidth: at 273 GB/s, it’s the slowest of the three when a model has to move a lot of data, and reviewers consistently find it underperforms Apple’s Mac Studio on raw token generation despite the mature software.

This fits teams already deep in the CUDA and TensorRT stack who want to prototype locally before deploying to NVIDIA cloud infrastructure without touching their code. For models, think quantized versions of Llama, Qwen and DeepSeek in the 70B to 200B range, where TensorRT-LLM optimization matters more than raw bandwidth.

AMD: one chip, two very different products

This is where things get confusing on purpose. AMD’s Ryzen AI Max+ 395 chip, marketed as “the world’s smallest AI development PC” capable of running 200-billion-parameter models locally, ships in two completely different products. Third-party mini PCs built around the same chip, like the GMKtec EVO-X2 and the Framework Desktop, sell for a fraction of AMD’s own official Ryzen AI Halo Developer Platform. Same processor, same 128GB of memory and more than double the price on the official kit.

LTT Labs, one of the more rigorous independent testing outfits, explains the gap plainly: the premium buys AMD’s curated software configurations, “AI Playbooks,” and first party support, not extra hardware. The advantage of the third party route is price. You get the same chip and memory pool for far less if you’re comfortable managing the software yourself. The advantage of AMD’s own kit is exactly that support layer, plus the promise of continued driver and playbook maintenance. The drawback, either way, is raw speed: LTT Labs found “the Apple Silicon Mac Studios outperform the AMD Ryzen AI Max+ 395 machines,” generating tokens two to three times slower in their testing.

There’s a software catch too, specific to the operating system. ROCm, AMD’s answer to CUDA, is still meaningfully more mature on Linux than on Windows. Windows support runs through WSL and a newer compatibility layer that only recently expanded to more Ryzen hardware, while Linux has had direct, better supported access for longer. This fits budget conscious developers who want a large memory pool for training and fine tuning experiments on Linux, and don’t need NVIDIA specific tooling. On the models side, AMD has actually leaned into this: Ryzen AI Max+ 395 was the first consumer processor to run OpenAI’s gpt-oss 120B, which needs around 61GB of memory at MXFP4 precision and runs at up to 30 tokens per second on the 128GB configuration.

Apple: the quiet winner on bandwidth

Apple’s Mac Studio comes with the M5 Max chip and up to 128GB of unified memory, or the M5 Ultra with up to 512GB. The real differentiator is memory bandwidth, and it’s worth being precise here since the two chips aren’t equal: The M5 Max reaches up to 614 GB/s, while the M5 Ultra doubles that to 1.2 TB/s. Even the lower tier beats NVIDIA and AMD’s local options at moving model data, which is why reviewers keep clocking the Mac Studio ahead of both rivals on local inference despite Apple never marketing these chips as AI accelerators first.

The advantage is that bandwidth, plus a memory ceiling (512GB on the Ultra) that lets you load models neither of the other two machines can hold without heavy quantization. The drawback is the ecosystem: Your code needs to run through Apple’s stack rather than CUDA or ROCm, which is a real cost if your team’s tooling already assumes one of those. That said, this doesn’t mean writing everything in MLX. Most people running models on a Mac just load GGUF files directly through llama.cpp’s Metal backend, Ollama or LM Studio, all of which work out of the box. MLX only matters if you’re optimizing specifically for Apple Silicon.

This fits developers who care more about inference speed and model size than ecosystem compatibility. For models, 512GB is enough to run a 70B model with zero quantization, which is a real advantage over the other two machines. It is not, however, enough for the largest open models.

The bottom line

None of these is a universal answer. If your code already runs on CUDA, NVIDIA removes the most risk. If you want the most memory for your money and you’re comfortable on Linux, AMD’s ecosystem, official kit or third party board, gets you there cheaper. If you want the fastest actual inference and don’t mind stepping outside CUDA and ROCm entirely, Apple quietly wins the benchmarks. Pick the ecosystem your workflow already depends on first. The hardware comparison only matters after that.

A local AI box isn’t there to replace the cloud for large-scale training. It exists for three specific things: keeping sensitive data off someone else’s servers, avoiding metered API costs when you’re iterating hundreds of times a day and getting a fixed, predictable machine you fully control instead of a shared, rate-limited one. Cloud GPUs still win for large training runs and burst capacity. A local box wins for prototyping, fine-tuning smaller models and running inference on data you’re not allowed to send anywhere else. That’s the tradeoff, and it decides which of these three ecosystems actually fits your work.

NVIDIA, AMD and Apple are all shipping new local AI hardware on a near-constant cycle right now. Let’s look at which machine actually makes sense for you.

NVIDIA: the safe, expensive default

The NVIDIA DGX Spark pairs 128GB of unified memory with a Grace Blackwell GB10 chip built around CUDA, which is still the deepest, most battle tested software ecosystem in AI. Existing PyTorch code, TensorRT and cuDNN pipelines run on it without modification, which is not something you can say about the other two options yet.