No — not on this device

Ornith 1.5 397B-A17B at Q4_K_M needs 224.1 GB against 96.0 GB usable, and the shortfall of 128.1 GB is more than 32 GB of system RAM can cover at a tolerable speed. A smaller sibling or a lower quantisation is the honest answer here.

Does not fit 8K context Q4_K_M · 223.2 GB MIT Released 19 Aug 2026 New this week

The flagship Ornith on the Qwen3.5 397B-A17B architecture, MIT-licensed. A 256 GB Mac Studio at Q4, and it is in the Ollama library.

What hardware do I need for Ornith 1.5 397B-A17B? →

Fits instead: Ornith 1.5 35B-A3B (20.9 GB) · Ornith 1.5 9B (6.1 GB)

The VRAM budget

weights 223.2 GB
Weights 223.2 GB KV cache @ 8K 0.23 GB Runtime overhead 0.6 GB Over budget 128.1 GB past 96.0 GB

Quantisation ladder

QuantWeightsTotal @ 8KMax contextTok/sQualityFit
Q8_0 392.8 GB 393.7 GB ~6.2 −0.1% ppl 297.7 GB over
Q6_K 303.2 GB 304.0 GB ~8.0 −0.4% ppl 208.0 GB over
Q5_K_M 262.0 GB 262.9 GB ~9.3 −0.8% ppl 166.9 GB over
Q4_K_M 223.2 GB 224.1 GB ~11 −1.9% ppl 128.1 GB over
Q3_K_M 180.7 GB 181.5 GB ~13 −5.4% ppl 85.5 GB over
Q2_K 154.8 GB 155.7 GB ~16 −15% ppl 59.7 GB over

Quality is the published perplexity delta against f16 weights. Max context assumes an f16 KV cache; q8_0 roughly doubles it. Only 15 of its 60 blocks keep a per-token KV cache; the rest are linear-attention, Mamba or convolution blocks with a fixed-size state.

How to run it

terminal
$ pip install mlx-lm
$ mlx_lm.generate --model mlx-community/Ornith-1.5-397B-4bit \
    --max-tokens 512 --prompt "Hello"

Apple's own array framework. The fastest path on Apple Silicon. More on MLX.

01Download is 223.2 GB. Keep it on an SSD — a first load off a spinning disk takes minutes.
02macOS caps what the GPU may wire down at about 96.0 GB of 128 GB. Raising it with iogpu.wired_limit_mb is possible, and risky.
03If it falls back to CPU silently, drop the context first, then step down a quantisation.
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