I wrote up how I run local LLMs, with numbers and a focus on running Qwen 3.6 and Gemma 4. I prefer Gemma 4 31b, even though the general consensus is that Qwen 3.6 is better for code, and it is better on most coding focused benchmarks...it doesn't seem to be for my use cases, Gemma feels smarter. And, with QAT, you get more smarts in less memory, so it's fast and runs on more hardware.
https://swelljoe.com/post/how-i-run-local-llms/
Currently, the sweet spot for self-hosted models is either Qwen 3.6 or Gemma 4, and those top out at 31B (Gemma) and 35B (for Qwen, but you want the dense Qwen 3.6 27B if you can run it as reasonable speed...the dense models are much smarter), so for now, a system with 64GB or 128GB is going to be running the same models. Going to a bigger model doesn't get you better performance because there aren't any better models that are a little bigger. I wish there was a ~70B or even ~120B MoE in the Qwen 3.6 or Gemma 4 families, as I've got a Strix Halo running a model that leaves a lot of memory on the table (and it's not very fast, to boot...an MoE would be faster, and hopefully smarter if it's a much bigger model, like double or triple sized).
In short, right now, 64GB is all you need for the best models you can self-host on anything short of five-figure machines, but, I wouldn't buy any hardware right now, if you can wait a while. Tokens from DeepSeek are so cheap, you can wait out the memory shortage and get access to models you could never host locally. And, OpenRouter always has free models in preview or just because that you can use lightly, as they're rate-limited (but your self-hosted models are going to be rate-limited, too, because a Mac Mini can't run models very fast). Google AI Studio has the Gemma 4 models for free too, also rate/usage limited.
Hmmm
Then I assumed for cost and battery/heat reasons that a Mini would be better than a laptop.
27B dense can fit on a consumer graphics card. Even without getting into various "intrusive" ways to shrink the size of a model (e.g. REAP), something like a NVFP4 quant of Qwen3.6 27b
https://huggingface.co/nvidia/Qwen3.6-27B-NVFP4
should fit within ~22GB of VRAM. So easily on a 5090. It would also fit on a 3090/4090, but iirc they don't have NVFP4 natively, so you would want a different quant for them.
you can see /r/LocalLLama for some discussions. See this (random) post about Qwen3.6-27B on a 3090 at ~100 tok/s
https://www.reddit.com/r/LocalLLaMA/comments/1ujo46r/qwen_36...
Note that it is possible you could still do this stuff with a mac, as there are ways of hooking up a eGPU to macs and using it for inference. My understanding is they're all fairly hacky though, so it would likely be preferrable to just get a 3090 (or a non-nvidia option, e.g. an AMD r9700 pro has ~32GB of VRAM for much cheaper than a 5090.
https://www.reddit.com/r/LocalLLaMA/comments/1u50hnm/qwen_27...
that seems considerably slower though (~30 tok/s). I don't know if that's an outlier/misconfigured setup or what. In general there will be much better resources for local setups using 3090s, as they're quite popular. Note that 3090s (but not 4090s nor 5090s) have NVLink, so you can network the cards fairly effectively. For this reason 2x 3090 setups are fairly popular as well. I've heard that club 3090 makes that relatively straightforward
https://github.com/noonghunna/club-3090
but don't have experience myself.