ATH-MaaS · vision language

OvisOCR2

ATH-MaaS/OvisOCR2

OvisOCR2 at Q4_K_M is exactly 529,297,280 bytes (0.49 GiB / 0.53 GB) — an effective 4.964 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
853M
Architecture
qwen35
24 layers
Context
262,144
native (config.json)
License
apache-2.0

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
IQ2_M0.35 GiB376,811,6483.534bartowski
IQ3_XXS0.40 GiB432,558,2084.057bartowski
Q3_K_S0.41 GiB435,363,2004.083prithivMLmods
Q2_K0.41 GiB442,482,8164.150bartowski
Q3_K_M0.43 GiB466,222,4644.373prithivMLmods
Q3_K_M0.43 GiB466,222,4644.373Abiray
IQ3_XS0.44 GiB476,110,9764.465bartowski
Q3_K_S0.45 GiB481,886,3364.519bartowski
IQ3_M0.45 GiB485,830,7844.556bartowski
Q3_K_L0.46 GiB491,322,7524.608prithivMLmods
Q3_K_M0.46 GiB496,263,2964.654bartowski
IQ4_XS0.47 GiB501,309,5684.702bartowski
Q2_K_L0.47 GiB504,066,1764.728bartowski
Q4_K_S0.47 GiB505,253,7604.739prithivMLmods
Q4_K_S0.47 GiB505,253,7604.739Abiray
Q3_K_L0.47 GiB507,076,7364.756bartowski
Q4_00.48 GiB515,768,4484.837bartowski
IQ4_NL0.48 GiB515,891,3284.838bartowski
Q4_K_M0.49 GiB529,297,2804.964Abiray
Q4_K_M0.49 GiB529,297,2804.964prithivMLmods
Q4_K_S0.49 GiB530,743,4244.978bartowski
Q4_10.51 GiB544,440,4485.106bartowski
Q4_K_M0.52 GiB557,867,1365.232bartowski
Q5_K_S0.52 GiB563,654,5285.286prithivMLmods
Q5_K_S0.52 GiB563,654,5285.286Abiray
Q5_K_M0.54 GiB577,998,7205.421prithivMLmods
Q5_K_M0.54 GiB577,998,7205.421Abiray
Q5_K_S0.55 GiB588,841,0885.523bartowski
Q4_K_L0.58 GiB619,450,4965.810bartowski
Q5_K_M0.58 GiB624,345,2165.856bartowski
Q6_K0.59 GiB629,744,0005.906Abiray
Q6_K0.62 GiB669,712,5126.281bartowski
Q5_K_L0.64 GiB685,928,5766.433bartowski
Q6_K_L0.68 GiB731,295,8726.859bartowski
Q8_00.76 GiB811,843,4567.614prithivMLmods
Q8_00.76 GiB811,843,4987.614Abiray
Q8_00.76 GiB813,576,3207.630bartowski
BF161.41 GiB1,516,744,57614.225prithivMLmods
BF161.41 GiB1,516,744,57614.225bartowski
F161.41 GiB1,516,744,57614.225prithivMLmods

KV cache by context

computed per layer
ContextKV cache (f16)Flat formulaOverstated byFull / windowed / recurrent
4,0960.05 GiB0.19 GiB4.00×6 / 0 / 18
8,1920.09 GiB0.38 GiB4.00×6 / 0 / 18
16,3840.19 GiB0.75 GiB4.00×6 / 0 / 18
32,7680.38 GiB1.50 GiB4.00×6 / 0 / 18
65,5360.75 GiB3.00 GiB4.00×6 / 0 / 18
131,0721.50 GiB6.00 GiB4.00×6 / 0 / 18

18 of 24 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 0.45 GiB. The real file is 0.49 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

from config.json
Layers
24
Attention heads
8
KV heads
2
Head dim
256
Hidden size
1024
Vocab
248,320
Sliding window
none
SWA period
MLA
no
Experts
Experts per token
use_sliding_window

Questions people ask

How much VRAM does OvisOCR2 need?
Q4_K_M is exactly 529,297,280 bytes (0.49 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
How large is OvisOCR2'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 OvisOCR2 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.