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Apple M4 Ultra (384GB)

The Apple M4 Ultra (384GB) has 384 GB VRAM and 1092 GB/s memory bandwidth. It can run 69 of our 70 tracked models natively in VRAM at 8k context.

With 384 GB LPDDR5X, the Apple M4 Ultra (384GB) is a workstation-tier GPU that can run 69 models natively. It handles 70B-class models at Q4 quantization.

The Apple M4 Ultra (384GB) is the maximum-memory configuration of Apple's M4 Ultra chip, available in the Mac Pro and Mac Studio. Its 384GB unified memory pool shared between CPU and GPU at 1,092 GB/s is large enough to hold the largest publicly available open-weight models — including 405B parameter models at Q4 quantization — entirely in memory without any offloading. MLX and llama.cpp's Metal backend both fully support this configuration for local frontier-scale inference.

Apple M4 Ultra (384GB): 2025 flagship workstation with 384GB unified memory at 1092 GB/s. 32-core CPU (24P+8E).

Runs 405B at Q4 native. 70B at ~25-35 t/s decode. Only platform for single-chip 405B inference.

MLX framework native. llama.cpp Metal fully optimized. No software quirks — current optimization target.

VendorApple
ArchitectureApple M4 Ultra
CPU cores32 (24P + 8E)
VRAM384 GB (unified)
Memory typeLPDDR5X
Memory bandwidth1092 GB/s
Compute backendMETAL
TierWorkstation
Released2025
Models (native)69 / 70
Models (offload)0 / 70
Software: MLX gives the best performance on Apple Silicon; llama.cpp Metal backend is a solid alternative. Both are well-supported by Ollama.

Popular models for this GPU

Models this GPU runs natively in VRAM (69)

Too large for this GPU (1)

Frequently asked questions

How much VRAM does the Apple M4 Ultra (384GB) have?
The Apple M4 Ultra (384GB) has 384 GB of LPDDR5X with 1092 GB/s memory bandwidth (unified system memory, shared between CPU and GPU).
What is the Apple M4 Ultra (384GB) best for?
With 384 GB of VRAM, the Apple M4 Ultra (384GB) is a server-class GPU designed for running the largest open-weight models (70B–405B) at high quantization with ample context.
What LLMs can the Apple M4 Ultra (384GB) run locally?
The Apple M4 Ultra (384GB) can run 69 of the 70 open-weight models tracked by CanItRun natively in VRAM at 8k context. Top options include: Llama 3.3 70B Instruct at FP32, Llama 3.1 8B Instruct at FP32, Llama 3.2 3B Instruct at FP32.
Can the Apple M4 Ultra (384GB) run Llama 3.3 70B Instruct?
Yes. The Apple M4 Ultra (384GB) runs Llama 3.3 70B Instruct natively in VRAM at FP32 quantization, achieving approximately 3.9 tokens per second.
Can the Apple M4 Ultra (384GB) run Qwen 3.6 27B?
Yes. The Apple M4 Ultra (384GB) runs Qwen 3.6 27B natively in VRAM at FP32 quantization, achieving approximately 10.1 tokens per second.
Can the Apple M4 Ultra (384GB) run Llama 3.1 8B Instruct?
Yes. The Apple M4 Ultra (384GB) runs Llama 3.1 8B Instruct natively in VRAM at FP32 quantization, achieving approximately 34.1 tokens per second.