Best local LLMs for Mac Studio M3 Ultra 512GB

Mac Studio M3 Ultra 512GB has 512GB of unified memory and is a strong fit for server-scale local AI on Apple silicon. These recommendations are generated from the current LocalClaw catalogue and filtered for realistic memory headroom.

Recommendations updated November 6, 2026

Silver Mac Studio in a dark studio setting
Mac Studio · M3 Ultra · 512GB unified memory
Chip
M3 Ultra
Unified memory
512GB
Compatible catalogue models
248
Best match
MiMo-V2.6-Flash-RL

Quick answer

Start with MiMo-V2.6-Flash-RL on this Mac. A comfortable or good fit leaves useful memory for macOS and your local runtime. A tight fit can still work, but close other apps, reduce context length when needed, and prefer the listed quantization.

Mac Studio · M3 Ultra · 512GB unified memory · 4TB SSD · Maximum Memory

Top compatible local LLMs

#1Best match

MiMo-V2.6-Flash-RL

Official Xiaomi MiMo MIT-licensed sparse MoE with 309B total / 15B active parameters, native text-image-video-audio support, 1M-token context and ggml-org GGUF artifacts for llama.cpp-class workstation experiments.

Parameters309B (15B active, MoE)Minimum RAM160GBQuantizationQ2_K GGUFModel size126.4GB
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#2Best match

DeepSeek V4.1 Flash

Official MIT DeepSeek V4.1 Flash release with CED architecture, CSA2 attention, multimodal input and 1M-token context. Community GGUF artifacts include split Q2_K/Q3/Q4 builds plus a llama.cpp patch path; use only on 256GB+ workstations, with 384GB+ safer.

Parameters552B MoE (8B/16B active)Minimum RAM256GBQuantizationQ2_KModel size246GB
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#3Best match

Xing4.0-29B-A4B

Official China Telecom XingChen-AGI Apache 2.0 MoE release with 29B total parameters, 4B active parameters, 256K native context and an official IQ4_NL GGUF path for llama.cpp-class local inference on 24GB GPU workstations.

Parameters29B (4B active, MoE)Minimum RAM32GBQuantizationIQ4_NL GGUFModel size20.1GB
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#4Best match

Occamy-1.0

Accio Lab Apache 2.0 co-work model post-trained from Qwen3.6-35B-A3B for long-horizon tools, files, code and business workflows. Official GGUF Q4_K_M is 19.7GiB with llama.cpp validation evidence.

Parameters35B (3B active, MoE)Minimum RAM32GBQuantizationQ4_K_MModel size19.7GB
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#5Best match

Nex-N2.5-mini

Official Nex-AGI Apache 2.0 multimodal agent model for computer use, web browsing, coding and tool calling. Community Q4_K_M GGUF is about 21.3GB with documented llama.cpp text and vision smoke tests.

Parameters35B MoEMinimum RAM32GBQuantizationQ4_K_MModel size21.3GB
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#6Best match

DeepSeek V4 Flash Vision Exp

Official MIT DeepSeek V4 Flash multimodal experiment with image understanding, 1M context and Unsloth Dynamic GGUF artifacts. The lightest practical GGUF is roughly 82-97GB, while higher-quality Q4/Q8 builds are about 155-162GB, so this belongs on large-memory workstations.

Parameters284B (13B active, multimodal MoE)Minimum RAM128GBQuantizationUD-Q2_K_XLModel size97GB
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#7Best match

DeepSeek V4 Flash 0731 (284B MoE)

Official MIT DeepSeek V4 Flash successor release with stronger agentic coding, DSpark speculative decoding support and a practical Unsloth Dynamic GGUF path. Still a large workstation/server local model: Q4 is about 155GB and Q8 is about 162GB.

Parameters284B (13B active)Minimum RAM256GBQuantizationUD-Q4_K_XLModel size155GB
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#8Best match

LFM2.5-24B-A2B

Liquid AI LFM2.5 reasoning MoE built for private on-device agents. The official LFM 1.0 release has 24B total / 2.45B active parameters, 131K context, official GGUF and MLX artifacts, and a 14.5GB Q4_K_M GGUF for laptop/workstation local use.

Parameters24B (2.45B active, MoE)Minimum RAM24GBQuantizationQ4_K_M GGUFModel size14.53GB
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#9Best match

GLM-5.2 (744B MoE)

Z.ai flagship open model for long-horizon coding, reasoning and agentic work. 744B total, 40B active, 1M-token context, MIT license. Unsloth Dynamic GGUF makes it technically local, but it needs workstation/server-class memory: ~245GB total memory for 2-bit and 372GB+ for 4-bit.

Parameters744B (40B active)Minimum RAM256GBQuantizationUD-IQ2_MModel size239GB
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How this order works

The shared LocalClaw engine first rejects hosted-only, excluded and oversized records. It reserves system and 8k-context headroom, labels comfortable, good and tight fits, then ranks the remaining models by hardware fit, use case, catalogue capability ratings, runtime and freshness. Community stars are never included. This is practical guidance, not a standardized third-party benchmark.

Browse the full model index

Buying note

This guide is about local AI fit, not live pricing. Prices and availability change. An Amazon link may be an affiliate link that supports LocalClaw at no extra cost. Confirm the exact memory and storage on Amazon before ordering.