Microsoft on Apple M3

Can I run Phi-4 14B on an Mac Studio M3 Ultra 256GB?

Yes. Phi-4 14B at Q4_K_M uses 10.5 GB of the 192.0 GB available on a Mac Studio M3 Ultra 256GB, and runs at about 51.0 tokens per second. You can push the context to 16K.

Runs comfortably

10.5 GB of 192.0 GB · 5%
0192 GB
Weights 8.4 GB
KV cache 1.6 GB
Runtime overhead 0.5 GB

Phi-4 14B at Q4_K_M leaves 181.5 GB spare on a Mac Studio M3 Ultra 256GB. There is room to raise the context length or move up a quantisation level.

Generation51.0tok/s
Prompt processing814tok/s
Max context16Ktokens
KV per 1K tokens0GB

Every quantisation of Phi-4 14B on a Mac Studio M3 Ultra 256GB

Highlighted row is the highest quality that still fits at 8K context.

QuantisationbpwWeights TotalVerdictMax ctxtok/s
FP16 / BF16 16.00 27.4 GB 29.5 GB Runs comfortably 16K 16.7
INT8 / W8A8 8.50 14.3 GB 16.4 GB Runs comfortably 16K 31.1
Q8_0 (GGUF) 8.50 14.3 GB 16.4 GB Runs comfortably 16K 31.1
FP8 (E4M3) 8.00 13.7 GB 15.8 GB Runs comfortably 16K 32.4
Q6_K 6.56 11.2 GB 13.3 GB Runs comfortably 16K 39.0
Q5_K_M 5.67 9.7 GB 11.8 GB Runs comfortably 16K 44.7
Q5_K_S 5.52 9.4 GB 11.5 GB Runs comfortably 16K 45.8
AWQ 4-bit 4.25 8.7 GB 10.8 GB Runs comfortably 16K 49.4
GPTQ 4-bit 4.25 8.7 GB 10.8 GB Runs comfortably 16K 49.4
MXFP4 4.25 8.7 GB 10.8 GB Runs comfortably 16K 49.4
Q4_K_M 4.85 8.4 GB 10.5 GB Runs comfortably 16K 51.0
Q4_K_S 4.58 7.9 GB 10.0 GB Runs comfortably 16K 53.5
Q4_0 4.55 7.9 GB 10.0 GB Runs comfortably 16K 53.8
IQ4_XS 4.25 7.4 GB 9.5 GB Runs comfortably 16K 56.9
Q3_K_M 3.91 6.9 GB 9.0 GB Runs comfortably 16K 60.9
IQ3_M 3.70 6.5 GB 8.6 GB Runs comfortably 16K 63.6
IQ3_XXS 3.06 5.5 GB 7.6 GB Runs comfortably 16K 73.7
Q2_K 2.63 4.8 GB 6.9 GB Runs comfortably 16K 82.5
IQ2_XXS 2.06 3.9 GB 6.0 GB Runs comfortably 16K 97.9
IQ1_M 1.75 3.4 GB 5.5 GB Runs comfortably 16K 109

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