How much VRAM does Qwen3.5 4B need?

Qwen3.5 4B (4B parameters) requires approximately 9.2 GB of memory with Q4_K_M quantization.

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

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

Can it run?

Yes, RTX A6000 48GB can run Qwen3.5 4B with a C grade (Runs well). Expected decode speed: 226.6 tok/s.

CUsable

Runs well

Using Q4_K_M in Ollama

Capabilities:

Fit status

Runs well

Decode

226.6 tok/s

TTFT

854 ms

Safe context

83K

Memory

9.2 GB / 48.0 GB

Weights2.4 GB

KV Cache0.8 GB

Runtime1.2 GB

Headroom4.8 GB

Workload	Grade	Fit	Decode	TTFT	Context
Agentic Coding	C	Runs well	239.2 tok/s	1177 ms	159K
Chat	C	Runs well	239.2 tok/s	441 ms	42K
Coding	C	Runs well	226.6 tok/s	854 ms	83K
RAG	C	Runs well	239.2 tok/s	1471 ms	159K
Reasoning	C	Runs well	239.2 tok/s	956 ms	83K

How Qwen3.5 4B (4B params) fits at each quantization level on RTX A6000 48GB (48.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	1.6 GB	Low	D30
Q3_K_S	3	2.0 GB	Low	D30
NVFP4	4

Upgrade options

MacBook Pro M4 Max 96GBBudget pick

C141 tok/s decode

~$2,499 MSRP

MacBook Pro M3 Max 128GBBest value

C98.4 tok/s decode

~$2,499 MSRP