How much VRAM does Qwen3.5 9B need?

Qwen3.5 9B (9B parameters) requires approximately 20.9 GB of memory with Q4_K_M quantization.

What is the best quantization for Qwen3.5 9B?

The recommended quantization for Qwen3.5 9B is Q4_K_M, which balances quality and memory efficiency.

Can it run?

Yes, AMD Instinct MI250X 128GB can run Qwen3.5 9B with a C grade (Runs well). Expected decode speed: 419.7 tok/s.

CUsable

Runs well

Using Q4_K_M in Ollama

Capabilities:

Fit status

Runs well

Decode

419.7 tok/s

TTFT

461 ms

Safe context

98K

Memory

20.9 GB / 128.0 GB

Weights5.5 GB

KV Cache1.4 GB

Runtime1.2 GB

Headroom12.8 GB

Workload	Grade	Fit	Decode	TTFT	Context
Agentic Coding	C	Runs well	454.6 tok/s	619 ms	184K
Chat	C	Runs well	454.6 tok/s	350 ms	50K
Coding	C	Runs well	419.7 tok/s	461 ms	98K
RAG	C	Runs well	454.6 tok/s	774 ms	184K
Reasoning	C	Runs well	454.6 tok/s	503 ms	98K

How Qwen3.5 9B (9B params) fits at each quantization level on AMD Instinct MI250X 128GB (128.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	3.5 GB	Low	D30
Q3_K_S	3	4.4 GB	Low	D30
NVFP4	4

HuggingFace

huggingface-cli download hf-lmstudio-community--qwen3-5-9b-gguf

Upgrade options

Mac Studio M3 Ultra 256GBBudget pick

C101.4 tok/s decode