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Reply To: [Solved] Local LLM / MLX Framework Unified Memory Allocation Out-of-Memory Panic on Mac Studio M2 Ultra: How to resolve macOS default wired memory limit restricting single-process unified VRAM allocation to 75%
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Home › Forums › Apple Silicon, Terminal & Developer Tools › [Solved] Local LLM / MLX Framework Unified Memory Allocation Out-of-Memory Panic on Mac Studio M2 Ultra: How to resolve macOS default wired memory limit restricting single-process unified VRAM allocation to 75% › Reply To: [Solved] Local LLM / MLX Framework Unified Memory Allocation Out-of-Memory Panic on Mac Studio M2 Ultra: How to resolve macOS default wired memory limit restricting single-process unified VRAM allocation to 75%
Walter SchulzeIncreasing sysctl wired memory limit and quantizing model weights for MLX runtime.
Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:
- Increase sysctl wired unified memory limit:
sudo sysctl iogpu.wired_mem_limit=180000 - Load models using 4-bit or 8-bit quantization (e.g.
mlx-lm.generate --model mlx-community/Llama-3-70B-4bit). - Flush system unified cache before heavy inference passes:
sudo purge
Following this procedure restores full stability with zero recurring log errors.