Question 1

Can RX 6900 XT 16GB run Qwen3.5 4B?

Accepted Answer

Yes, RX 6900 XT 16GB can run Qwen3.5 4B with a C grade (Runs well). Expected decode speed: 151.1 tok/s.

Question 2

How much VRAM does Qwen3.5 4B need?

Accepted Answer

Qwen3.5 4B (4B parameters) requires approximately 6.0 GB of memory with Q4_K_M quantization.

Question 3

What is the best quantization for Qwen3.5 4B?

Accepted Answer

The recommended quantization for Qwen3.5 4B is Q4_K_M, which balances quality and memory efficiency.

Workload	Grade	Fit	Decode	TTFT	Context
Agentic Coding	C	Runs well	119.6 tok/s	2354 ms	79K
Chat	C	Runs well	119.6 tok/s	883 ms	21K
Coding	C	Runs well	151.1 tok/s	1281 ms	42K
RAG	C	Runs well	119.6 tok/s	2943 ms	79K
Reasoning	C	Runs well	119.6 tok/s	1913 ms	42K

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	1.6 GB	Low	D32
Q3_K_S	3	2.0 GB	Low	D32
NVFP4	4

Can RX 6900 XT 16GB run Qwen3.5 4B?

Memory breakdown