Is Qwen3.5-2B or Qwen3-1.7B smaller?

Qwen3-1.7B is smaller at Q4_K_M: 1.03 GiB against 1.22 GiB.

Which uses less memory at long context?

Qwen3.5-2B — its KV cache at 32K context is 9.3x smaller, because of how its attention layers cache.

Model comparison

Qwen3.5-2B vs Qwen3-1.7B

At Q4_K_M, Qwen3-1.7B is the smaller download — 1,107,409,472 bytes against 1,312,164,384. At long context the gap widens: Qwen3.5-2B's KV cache at 32K is 9.3× smaller, which usually matters more than the difference in weights.

From the file· summed bytes, KV per layer

Side by side

	Qwen3.5-2B	Qwen3-1.7B
Parameters	2.3B	2.0B
Architecture	qwen35	qwen3
Layers	24	28
Native context	262,144	40,960
Mixture of experts	no	no
Quantizations published	38	48
Smallest quantization	0.75 GiB	0.50 GiB
Q4_K_M	1.22 GiB	1.03 GiB
Licence	—	—

KV cache by context

the term that decides long-context viability

Context	Qwen3.5-2B	Qwen3-1.7B	Ratio
4,096	0.05 GiB	0.44 GiB	9.33×
8,192	0.09 GiB	0.88 GiB	9.33×
16,384	0.19 GiB	1.75 GiB	9.33×
32,768	0.38 GiB	3.50 GiB	9.33×
65,536	0.75 GiB	7.00 GiB	9.33×
131,072	1.50 GiB	14.00 GiB	9.33×