text model · phi · macOS
Can I run Phi-4 14B on Apple M3 Ultra (256GB)?
Yes. Phi-4 14B runs on Apple M3 Ultra (256GB) at Q4_K_M (~10.8 GB of ~192 GB usable).
Runs at Q4_K_M using ~10.8 GB of ~192 GB usable. You have room for FP16 for higher quality.
That figure is at a 4k context and moves about ±15% as context length changes. Apple M3 Ultra (256GB) leaves ~181.2 GB of headroom, room to step up to FP16 for higher quality.
- Q4_K_M needed
- ~10.8 GB
- Usable on device
- ~192 GB
- Device memory
- 256 GB
- Best quant
- Q4_K_M
Which quant fits
Running cost · estimate
- Power draw
- ~270 W
- Electricity / 1M tokens
- ~$0.16
- Pays for itself after
- ~11,762M tok
At ~$0.15/kWh and the estimated ~72 tok/s, a million generated tokens costs about $0.16 in electricity. Versus a hosted API at ~$0.5 per million tokens, the ~$3,999 Apple M3 Ultra (256GB) pays for itself after roughly 11,762 million tokens, so local hardware is mostly a fixed cost, not a per-token one. TDP is the peak draw, so this is an upper bound. Assumptions.
Run it
Pick your tool. All 3 load the same Q4_K_M weights.
ollama run phi4:14b llama-cli -hf bartowski/phi-4-GGUF:Q4_K_M lms get bartowski/phi-4-GGUF - Parameters
- 14B
- Q4_K_M size
- 9.05 GB
- Q8_0 size
- 15.58 GB
- Context
- 16k
- Ollama tag
- phi4:14b
- Memory
- 256 GB unified
- Usable for weights
- ~192 GB
- Power draw
- ~270 W
- Best runtime
- MLX direct / Ollama (MLX backend)
You could also run
Run Phi-4 14B on other hardware
FAQ
Can Apple M3 Ultra (256GB) run Phi-4 14B?
Yes. Phi-4 14B runs on Apple M3 Ultra (256GB) at Q4_K_M (~10.8 GB of ~192 GB usable).
How much memory does Phi-4 14B need?
Apple M3 Ultra (256GB) has room to spare. At Q4_K_M the weights are ~9.05 GB; with KV cache and runtime overhead, budget ~10.8 GB at a 4k context.
What is the best tool to run Phi-4 14B on macOS?
LM Studio for a simple setup; mlx-lm for the most speed. vLLM is NOT a Mac tool, it is a CUDA/Linux serving engine. Unified memory is not a fixed VRAM slice; ~70% is usable for weights.
Embed this
A live badge for your model card or README, updated as the data is. [](https://localmodel.run/can-i-run/phi-4-14b/apple-m3-ultra-256gb) Sources
Weights are measured from GGUF files; KV cache and overhead are computed, so totals can vary ~15% with context and runtime. Any tok/s is a bandwidth estimate. See methodology.