Qwen · vision language · mixture of experts

Qwen3.5-35B-A3B

Qwen/Qwen3.5-35B-A3B

Qwen3.5-35B-A3B at Q4_K_M is exactly 21,169,116,992 bytes (19.72 GiB / 21.17 GB) — an effective 4.711 bits per weight, not the nominal 4. Its KV cache at 32K is 0.63 GiB.

From the file· summed from 1 file(s)From the file· KV per layer
Parameters
36.0B
total, not active
Architecture
qwen35moe
40 layers
Context
262,144
native (config.json)
License
apache-2.0

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
IQ1_M8.77 GiB9,421,649,7282.096bartowski
UD-IQ2_XXS9.93 GiB10,656,955,0082.371unsloth
IQ2_XXS9.94 GiB10,676,139,8402.376bartowski
UD-IQ2_M10.61 GiB11,391,613,5682.535unsloth
IQ2_XS10.89 GiB11,694,831,4242.602bartowski
IQ2_S11.09 GiB11,907,962,6882.650bartowski
IQ2_M12.07 GiB12,964,403,0082.885bartowski
UD-IQ3_XXS12.18 GiB13,080,066,6882.911unsloth
Q2_K12.58 GiB13,506,778,9443.006bartowski
UD-IQ3_S12.65 GiB13,583,383,1683.023unsloth
Q2_K_L13.04 GiB14,003,418,9443.116bartowski
Q3_K_S14.22 GiB15,265,856,1283.397unsloth
IQ3_XXS14.68 GiB15,761,446,7203.507bartowski
Q3_K_M15.23 GiB16,356,375,1683.640733unsloth
Q3_K_S15.28 GiB16,404,920,1283.650bartowski
IQ3_XS15.94 GiB17,110,087,4883.807bartowski
Q3_K_M15.94 GiB17,117,951,8083.809753bartowski
UD-IQ4_XS16.29 GiB17,486,174,8483.891unsloth
Q3_K_L16.56 GiB17,777,899,3283.956bartowski
IQ3_M16.57 GiB17,791,661,8883.959bartowski
UD-IQ4_NL16.60 GiB17,821,719,1683.966unsloth
IQ4_XS18.35 GiB19,699,554,1124.383753bartowski
UD-Q4_K_L18.82 GiB20,205,632,1604.496unsloth
Q4_K_S19.25 GiB20,673,845,8884.600unsloth
IQ4_NL19.33 GiB20,754,978,6244.618bartowski
Q4_019.41 GiB20,836,243,2644.636753bartowski
Q4_K_M19.72 GiB21,169,116,9924.711733lmstudio-community
Q4_K_S20.01 GiB21,486,360,3844.781bartowski
Q4_K_M20.50 GiB22,016,023,1684.899unsloth
Q4_K_M20.75 GiB22,285,080,3844.959753bartowski
Q4_K_L21.11 GiB22,662,526,7845.043bartowski
Q4_121.30 GiB22,868,449,0885.089bartowski
Q5_K_S23.12 GiB24,823,544,4485.524unsloth
Q5_K_S23.33 GiB25,051,879,2325.574bartowski
Q5_K_M24.13 GiB25,913,186,1125.766753bartowski
Q5_K_L24.43 GiB26,227,062,5925.836bartowski
Q5_K_M24.45 GiB26,249,607,8085.841733unsloth
Q6_K26.56 GiB28,514,152,2566.345733lmstudio-community
UD-Q6_K_S26.56 GiB28,515,105,4406.345unsloth
Q6_K26.87 GiB28,852,861,5686.420unsloth

KV cache by context

computed per layer
ContextKV cache (f16)Flat formulaOverstated byFull / windowed / recurrent
4,0960.08 GiB0.31 GiB4.00×10 / 0 / 30
8,1920.16 GiB0.63 GiB4.00×10 / 0 / 30
16,3840.31 GiB1.25 GiB4.00×10 / 0 / 30
32,7680.63 GiB2.50 GiB4.00×10 / 0 / 30
65,5361.25 GiB5.00 GiB4.00×10 / 0 / 30
131,0722.50 GiB10.00 GiB4.00×10 / 0 / 30

30 of 40 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 18.83 GiB. The real file is 19.72 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

from config.json
Layers
40
Attention heads
16
KV heads
2
Head dim
256
Hidden size
2048
Vocab
248,320
Sliding window
none
SWA period
MLA
no
Experts
256
Experts per token
8
use_sliding_window

Questions people ask

How much VRAM does Qwen3.5-35B-A3B need?
Q4_K_M is exactly 21,169,116,992 bytes (19.72 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
How large is Qwen3.5-35B-A3B's KV cache?
0.63 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.
Is Qwen3.5-35B-A3B a mixture-of-experts model?
Yes — 256 experts, 8 routed per token. Every expert must be resident, but only the routed ones are read per token, which is why its memory requirement and its speed behave very differently.
Which quantization of Qwen3.5-35B-A3B 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.