Is Qwen3.5-4B-DFlash or Qwen3-0.6B smaller?

Qwen3.5-4B-DFlash is smaller at Q4_K_M: 0.36 GiB against 0.37 GiB.

Which uses less memory at long context?

Qwen3.5-4B-DFlash — its KV cache at 32K context is 16.4x smaller, because of how its attention layers cache.

Model comparison

Qwen3.5-4B-DFlash vs Qwen3-0.6B

At Q4_K_M, Qwen3.5-4B-DFlash is the smaller download — 381,456,064 bytes against 396,705,472. At long context the gap widens: Qwen3.5-4B-DFlash's KV cache at 32K is 16.4× smaller, which usually matters more than the difference in weights.

From the file· summed bytes, KV per layer

Side by side

	Qwen3.5-4B-DFlash	Qwen3-0.6B
Parameters	634M	752M
Architecture	dflash	qwen3
Layers	6	28
Native context	262,144	40,960
Mixture of experts	no	no
Quantizations published	8	44
Smallest quantization	0.23 GiB	0.20 GiB
Q4_K_M	0.36 GiB	0.37 GiB
Licence	apache-2.0	—

KV cache by context

the term that decides long-context viability

Context	Qwen3.5-4B-DFlash	Qwen3-0.6B	Ratio
4,096	0.09 GiB	0.44 GiB	4.67×
8,192	0.12 GiB	0.88 GiB	7.34×
16,384	0.15 GiB	1.75 GiB	11.64×
32,768	0.21 GiB	3.50 GiB	16.44×
65,536	0.34 GiB	7.00 GiB	20.72×
131,072	0.59 GiB	14.00 GiB	23.81×