microsoft · vision language

Fara1.5-27B

microsoft/Fara1.5-27B

Fara1.5-27B at Q4_K_M is exactly 16,547,399,232 bytes (15.41 GiB / 16.55 GB) — an effective 4.839 bits per weight, not the nominal 4. Its KV cache at 32K is 2.00 GiB.

From the file· summed from 1 file(s)From the file· KV per layer
Parameters
27.4B
Architecture
qwen35
64 layers
Context
262,144
native (config.json)
License
mit

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
IQ2_M9.90 GiB10,634,372,9283.110bartowski
Q2_K9.98 GiB10,711,664,1923.132prithivMLmods
Q2_K10.80 GiB11,600,455,4883.392bartowski
Q3_K_S11.24 GiB12,073,952,8323.531prithivMLmods
IQ3_XXS11.54 GiB12,387,788,6083.623bartowski
Q2_K_L11.96 GiB12,842,055,4883.755bartowski
IQ3_XS12.19 GiB13,091,419,9683.828bartowski
Q3_K_M12.39 GiB13,301,442,1123.890prithivMLmods
Q3_K_M12.39 GiB13,301,442,1593.890Abiray
Q3_K_S12.56 GiB13,481,359,1683.942bartowski
IQ3_M12.73 GiB13,664,532,2883.996bartowski
Q3_K_L13.36 GiB14,344,775,2324.195prithivMLmods
Q3_K_M13.38 GiB14,366,750,5284.201bartowski
Q3_K_L14.01 GiB15,040,460,6084.398bartowski
IQ4_XS14.28 GiB15,328,839,4884.483bartowski
Q4_014.41 GiB15,476,868,6724.526prithivMLmods
Q4_K_S14.52 GiB15,586,313,7924.558prithivMLmods
Q4_K_S14.52 GiB15,586,313,8394.558Abiray
IQ4_NL14.98 GiB16,086,845,2484.704bartowski
Q4_015.00 GiB16,109,782,8484.711bartowski
Q4_K_S15.34 GiB16,474,163,0084.818bartowski
Q4_K_M15.41 GiB16,547,399,2324.839prithivMLmods
Q4_K_M15.41 GiB16,547,399,2794.839Abiray
Q4_K_M16.33 GiB17,533,552,4485.127bartowski
Q4_116.38 GiB17,586,472,7685.143bartowski
Q4_K_L17.21 GiB18,477,168,4485.403bartowski
Q5_K_S17.40 GiB18,679,612,9925.463prithivMLmods
Q5_017.40 GiB18,679,612,9925.463prithivMLmods
Q5_K_S17.40 GiB18,679,613,0395.463Abiray
Q5_K_M17.91 GiB19,231,098,4325.624prithivMLmods
Q5_K_M17.91 GiB19,231,098,4795.624Abiray
Q5_K_S18.11 GiB19,441,960,7685.686bartowski
Q5_K_M19.10 GiB20,513,802,0485.999bartowski
Q5_K_L19.84 GiB21,298,493,2486.228bartowski
Q6_K20.57 GiB22,082,528,8326.458prithivMLmods
Q6_K20.57 GiB22,082,528,8776.458Abiray
Q6_K21.63 GiB23,224,145,7286.792bartowski
Q6_K_L22.20 GiB23,839,979,3286.972bartowski
Q8_026.63 GiB28,595,762,7528.362prithivMLmods
Q8_026.63 GiB28,595,762,7978.362Abiray

KV cache by context

computed per layer
ContextKV cache (f16)Flat formulaOverstated byFull / windowed / recurrent
4,0960.25 GiB1.00 GiB4.00×16 / 0 / 48
8,1920.50 GiB2.00 GiB4.00×16 / 0 / 48
16,3841.00 GiB4.00 GiB4.00×16 / 0 / 48
32,7682.00 GiB8.00 GiB4.00×16 / 0 / 48
65,5364.00 GiB16.00 GiB4.00×16 / 0 / 48
131,0728.00 GiB32.00 GiB4.00×16 / 0 / 48

48 of 64 layers use linear attention, which keeps a fixed-size recurrent state instead of a per-token cache. Those layers do not grow with context at all — treating them as ordinary attention, as a flat formula does, overstates this model's cache by roughly 4.0× at long context.

Compare with

same modality, comparable size

Will it run on your card?

full quant x context sweep

Why other calculators give a different number

A parameters × bits ÷ 8 estimate puts Q4_K_M at roughly 14.33 GiB. The real file is 15.41 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

from config.json
Layers
64
Attention heads
24
KV heads
4
Head dim
256
Hidden size
5120
Vocab
248,320
Sliding window
none
SWA period
MLA
no
Experts
Experts per token
use_sliding_window

Questions people ask

How much VRAM does Fara1.5-27B need?
Q4_K_M is exactly 16,547,399,232 bytes (15.41 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
How large is Fara1.5-27B's KV cache?
2.00 GiB at 32K context with an f16 cache, computed per layer. Quantizing the cache to q8_0 roughly halves it, which is often the difference between a context length fitting and not.
Which quantization of Fara1.5-27B should I use?
Q4_K_M is the usual default. Pick the largest quantization that fits your card at the context you actually need — the table above gives exact sizes for every one published.