Is Yi-1.5-6B-Chat or Qwen3-4B smaller?

Qwen3-4B is smaller at Q4_K_M: 2.33 GiB against 3.42 GiB.

Which uses less memory at long context?

Yi-1.5-6B-Chat — its KV cache at 32K context is 2.3x smaller, because of how its attention layers cache.

Model comparison

Yi-1.5-6B-Chat vs Qwen3-4B

At Q4_K_M, Qwen3-4B is the smaller download — 2,497,280,256 bytes against 3,673,968,512. At long context the gap widens: Yi-1.5-6B-Chat's KV cache at 32K is 2.3× smaller, which usually matters more than the difference in weights.

From the file· summed bytes, KV per layer

Side by side

	Yi-1.5-6B-Chat	Qwen3-4B
Parameters	6.1B	4.0B
Architecture	llama	qwen3
Layers	32	36
Native context	4,096	40,960
Mixture of experts	no	no
Quantizations published	29	29
Smallest quantization	2.18 GiB	1.01 GiB
Q4_K_M	3.42 GiB	2.33 GiB
Licence	—	—

KV cache by context

the term that decides long-context viability

Context	Yi-1.5-6B-Chat	Qwen3-4B	Ratio
4,096	0.25 GiB	0.56 GiB	2.25×
8,192	0.50 GiB	1.13 GiB	2.25×
16,384	1.00 GiB	2.25 GiB	2.25×
32,768	2.00 GiB	4.50 GiB	2.25×
65,536	4.00 GiB	9.00 GiB	2.25×
131,072	8.00 GiB	18.00 GiB	2.25×