Can the Apple M1 Ultra run LFM2.5-2.6B?
IT FITS
Yes. 9 of 9 formats evaluated fit in 128 GB, the largest Apple M1 Ultra configuration, at 8,192 tokens. 4 of them are sized from a published file; the rest are rebuilt from the pinned architecture. The best quality that fits is FP16, needing 6.33 GB and running at an estimated 78 tokens per second.
Fitting in memory is not the same as loading. Whether the runtime and version you have supports this architecture and format on this machine has not been tested here.
Find the Apple M1 Ultra: Amazon ↗ · eBay (new and used) ↗Store links may pay us a commission. They never decide which card is suggested — the memory arithmetic does.
How long a conversation. At FP16, this pair holds 131,072 tokens of context — roughly 98,304 words — needing 8.34 GB. That is LiquidAI's own configured maximum of 131,072 tokens, not the card running out. A larger device does not extend it; a documented RoPE or YaRN extension might, and is a separate question from this one.
By memory configuration
The Apple M1 Ultra is sold with 64 or 128 GB of unified memory, and the amount decides the fit. Each row is the best format that fits in that much at 8,192 tokens, whole model resident.
Every format evaluated
4 of them are sized from a published file; the rest are rebuilt from the pinned architecture. The Basis column says which is which for each row. Decode and first-token figures are calibrated estimates, not runs on this card.
| Format | Needs | Of 128 GB | Fits | Decode | First token | Basis |
|---|---|---|---|---|---|---|
| FP16 | 6.33 GB | 5% | yes | ~78 tok/s | no comparable peak | size range |
| Q8_0 | 3.81 GB | 3% | yes | ~111 tok/s | no comparable peak | published data |
| Q6_K | 3.16 GB | 2% | yes | ~123 tok/s | no comparable peak | published data |
| Q5_K_M | 2.87 GB | 2% | yes | ~120 tok/s | no comparable peak | published data |
| Q5_0 | 2.82 GB | 2% | yes | ~121 tok/s | no comparable peak | size range |
| Q4_K_M | 2.61 GB | 2% | yes | ~125 tok/s | no comparable peak | published data |
| Q4_0 | 2.50 GB | 2% | yes | ~127 tok/s | no comparable peak | size range |
| Q3_K_M | 2.28 GB | 2% | yes | ~131 tok/s | no comparable peak | size range |
| Q2_K | 2.00 GB | 2% | yes | ~138 tok/s | no comparable peak | size range |
Sized at 8,192 tokens of context with the whole model resident — weights, the KV cache and the runtime reserve, offload off. Speed is only quoted for a format that fits: a rate for a configuration that cannot load is not a fact about anything.
Why the first-token figure is the same on every row
First token is modelled from the arithmetic the prompt requires, and that count does not change with the weight format — which is why it reads the same on every row. Real prefill does vary by format, because a quantized matmul is a different kernel; this model does not capture that, and the figure should be read as an order of magnitude rather than a ranking between formats.
What the labels mean
- published data
- Read from a published source — a file's byte count, a model's configuration or a manufacturer's specification — or exact arithmetic on such values. Not a measurement on a machine.
- reconstructed size
- Weight size reconstructed from the pinned architecture, because no published file exists.
- size range
- Only a lower and an upper bound are claimed for this weight size.
- estimate
- Calculated from sourced inputs by a stated method; an estimate, not a measurement.
This page fixes the context at 8,192 tokens and one device. Batch, concurrent users, KV-cache format, clusters and rental cost are all in the calculator, already set to this pairing.
Open in the calculator →Everything the Apple M1 Ultra runsBest models for 128 GB
LFM2.5-2.6B’s architecture is read from its publisher’s own config.json at a pinned revision, and the Apple M1 Ultra’s 128 GB and 800 GB/s come from the manufacturer’s specification. How far each figure can be trusted is published, per format and worst case included, on the accuracy scorecard.
Building this into your own product? A free API key returns exactly these figures, and the widget puts this answer on a product page with one script tag.
Use this answer in your own product
curl -s https://llmbottleneck.com/v1/analyze \
-H "Authorization: Bearer $LLMB_KEY" -H "content-type: application/json" \
-d '{"model":"liquidai-lfm2-5-2-6b","quantization":"FP16","context":8192,"hardware":"apple-m1-ultra"}'Same engine, same evidence, every field sourced. Free key in one step →
<script src="https://llmbottleneck.com/widget.js" data-model="liquidai-lfm2-5-2-6b" data-quantization="FP16" data-hardware="apple-m1-ultra" data-context="8192"></script>
No key needed. Unbranded, with your own buy button, on Pro and Business →