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LFM-2.5-1.2b-Instruct-roleplay-tuned

Indexnusrefather/LFM-2.5-1.2b-Instruct-roleplay-tuned

LFM-2.5-1.2b-Instruct-roleplay-tuned at Q4_K_M is exactly 730,896,288 bytes (0.68 GiB / 0.73 GB) — an effective 4.996 bits per weight, not the nominal 4. Its KV cache at 32K is 0.38 GiB.

From the file· summed from 1 file(s)From the file· KV per layer
Parameters
1.2B
Architecture
lfm2
16 layers
Context
128,000
native (config.json)
License
other

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
I1-IQ1_S0.28 GiB304,388,3202.081mradermacher
I1-IQ1_M0.30 GiB327,145,6962.236mradermacher
I1-IQ2_XXS0.34 GiB365,074,6562.495mradermacher
I1-IQ2_XS0.37 GiB396,204,2562.708mradermacher
I1-IQ2_S0.38 GiB403,790,0482.760mradermacher
I1-IQ2_M0.40 GiB434,133,2162.968mradermacher
I1-Q2_K_S0.43 GiB460,806,3683.150mradermacher
Q2_K0.45 GiB483,399,5843.304mradermacher
I1-Q2_K0.45 GiB483,399,9043.304mradermacher
I1-IQ3_XXS0.46 GiB490,985,6963.356mradermacher
I1-IQ3_XS0.50 GiB537,811,1683.676mradermacher
Q3_K_S0.52 GiB558,159,7763.815mradermacher
I1-IQ3_S0.52 GiB558,160,0963.815mradermacher
I1-Q3_K_S0.52 GiB558,160,0963.815mradermacher
I1-IQ3_M0.53 GiB566,794,4643.874mradermacher
Q3_K_M0.56 GiB600,348,5764.104mradermacher
I1-Q3_K_M0.56 GiB600,348,8964.104mradermacher
Q3_K_L0.59 GiB635,475,8724.344mradermacher
I1-Q3_K_L0.59 GiB635,476,1924.344mradermacher
I1-IQ4_XS0.62 GiB663,378,1444.535mradermacher
IQ4_XS0.62 GiB668,620,7044.570mradermacher
I1-IQ4_NL0.65 GiB695,752,9284.756mradermacher
I1-Q4_00.65 GiB697,850,0804.770mradermacher
Q4_K_S0.65 GiB700,471,2004.788mradermacher
I1-Q4_K_S0.65 GiB700,471,5204.788mradermacher
Q4_K_M0.68 GiB730,896,2884.996mradermacher
I1-Q4_K_M0.68 GiB730,896,6084.996mradermacher
I1-Q4_10.71 GiB760,502,4965.199mradermacher
Q5_K_S0.77 GiB825,251,7445.641mradermacher
I1-Q5_K_S0.77 GiB825,252,0645.641mradermacher
Q5_K_M0.79 GiB843,356,0645.765mradermacher
I1-Q5_K_M0.79 GiB843,356,3845.765mradermacher
Q6_K0.90 GiB962,844,5766.582mradermacher
I1-Q6_K0.90 GiB962,844,8966.582mradermacher
Q8_01.16 GiB1,246,255,0088.519mradermacher
F162.18 GiB2,343,327,64816.018mradermacher

KV cache by context

computed per layer
ContextKV cache (f16)Flat formulaOverstated byFull / windowed / recurrent
4,0960.05 GiB0.13 GiB2.67×6 / 0 / 10
8,1920.09 GiB0.25 GiB2.67×6 / 0 / 10
16,3840.19 GiB0.50 GiB2.67×6 / 0 / 10
32,7680.38 GiB1.00 GiB2.67×6 / 0 / 10
65,5360.75 GiB2.00 GiB2.67×6 / 0 / 10
131,0721.50 GiB4.00 GiB2.67×6 / 0 / 10

10 of 16 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 2.7× 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 0.61 GiB. The real file is 0.68 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

from config.json
Layers
16
Attention heads
32
KV heads
8
Head dim
64
Hidden size
2048
Vocab
65,536
Sliding window
none
SWA period
MLA
no
Experts
Experts per token
use_sliding_window

Questions people ask

How much VRAM does LFM-2.5-1.2b-Instruct-roleplay-tuned need?
Q4_K_M is exactly 730,896,288 bytes (0.68 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
How large is LFM-2.5-1.2b-Instruct-roleplay-tuned's KV cache?
0.38 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 LFM-2.5-1.2b-Instruct-roleplay-tuned 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.