google · vision language

gemma-3-12b-it

google/gemma-3-12b-it

gemma-3-12b-it at Q4_K_M is exactly 7,300,574,976 bytes (6.80 GiB / 7.30 GB) — an effective 4.792 bits per weight, not the nominal 4. Its KV cache at 32K is 2.47 GiB, not the 12.00 GiB a flat formula predicts.

From the file· summed from 1 file(s)From the file· KV from mirror (mirror:unsloth/gemma-3-12b-it)
Parameters
12.2B
Architecture
gemma3
48 layers
Context
131,072
native (config.json)
License
gemma

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
UD-IQ1_S2.85 GiB3,057,668,5762.007unsloth
UD-IQ1_M3.03 GiB3,249,207,7762.133unsloth
UD-IQ2_XXS3.36 GiB3,604,238,8162.366unsloth
UD-IQ2_M4.07 GiB4,366,371,2962.866unsloth
Q2_K4.44 GiB4,768,221,5363.130unsloth
Q2_K_L4.44 GiB4,768,221,5363.130unsloth
UD-IQ3_XXS4.50 GiB4,834,206,1763.173unsloth
Q3_K_S5.08 GiB5,458,315,6163.583unsloth
Q3_K_M5.60 GiB6,008,818,0163.944626unsloth
Q3_K_L6.03 GiB6,479,982,3364.254lmstudio-community
IQ4_XS6.10 GiB6,550,964,5764.300626unsloth
IQ4_NL6.41 GiB6,887,164,2564.521unsloth
Q4_06.43 GiB6,909,282,6564.535unsloth
Q4_K_S6.46 GiB6,935,333,2164.553unsloth
Q4_K_M6.80 GiB7,300,574,9764.792626lmstudio-community
Q4_K_M6.80 GiB7,300,778,3364.792626unsloth
Q4_17.04 GiB7,559,563,6164.962unsloth
Q4_07.52 GiB8,074,473,9205.300google
Q5_K_S7.67 GiB8,231,962,9765.404unsloth
Q5_K_M7.87 GiB8,445,036,8965.543626unsloth
Q6_K9.00 GiB9,660,608,2566.341626lmstudio-community
Q6_K9.00 GiB9,660,811,6166.341unsloth
Q8_011.65 GiB12,509,949,6968.212626lmstudio-community
Q8_011.65 GiB12,510,212,5768.212626unsloth
BF1621.92 GiB23,540,151,52015.452unsloth

KV cache by context

computed per layer — this model uses sliding-window attention
ContextKV cache (f16)Flat formulaOverstated byFull / windowed / recurrent
4,0960.72 GiB1.50 GiB2.09×8 / 40 / 0
8,1920.97 GiB3.00 GiB3.10×8 / 40 / 0
16,3841.47 GiB6.00 GiB4.09×8 / 40 / 0
32,7682.47 GiB12.00 GiB4.86×8 / 40 / 0
65,5364.47 GiB24.00 GiB5.37×8 / 40 / 0
131,0728.47 GiB48.00 GiB5.67×8 / 40 / 0

40 of 48 layers cache only a 1,024-token window rather than the full context, on a period of 6. Figures assume the default configuration; --swa-full disables the saving entirely.

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 6.38 GiB. The real file is 6.80 GiB, because a quantization is a mixture and some tensors are always kept at higher precision. The larger discrepancy is the cache: a flat formula gives 12.00 GiB at 32K context where the real figure is 2.47 GiB, because most of this model's layers cache a fixed window rather than the whole context.

Architecture

from mirror:unsloth/gemma-3-12b-it
Layers
48
Attention heads
16
KV heads
8
Head dim
256
Hidden size
3840
Vocab
262,208
Sliding window
1024
SWA period
6
MLA
no
Experts
Experts per token
use_sliding_window

Questions people ask

How much VRAM does gemma-3-12b-it need?
Q4_K_M is exactly 7,300,574,976 bytes (6.80 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
How large is gemma-3-12b-it's KV cache?
2.47 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 gemma-3-12b-it 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.
gemma-3-12b-it — VRAM requirements, exact quant sizes — ossmodeldb