How much VRAM does Qwen3.5 27B need?

Qwen3.5 27B (27B parameters) requires approximately 28.8 GB of memory with Q4_K_M quantization.

What is the best quantization for Qwen3.5 27B?

The recommended quantization for Qwen3.5 27B is Q4_K_M, which balances quality and memory efficiency.

Can it run?

Yes, Mac Studio M1 Ultra 64GB can run Qwen3.5 27B with a C grade (Runs well). Expected decode speed: 31.6 tok/s.

CUsable

Runs well

Using Q4_K_M in Ollama

Capabilities:

Fit status

Runs well

Decode

31.6 tok/s

TTFT

6132 ms

Safe context

26K

Memory

28.8 GB / 46.1 GB

Weights16.5 GB

KV Cache4.2 GB

Runtime1.2 GB

Headroom6.9 GB

Workload	Grade	Fit	Decode	TTFT	Context
Agentic Coding	C	Runs well	26.7 tok/s	10541 ms	45K
Chat	C	Runs well	26.7 tok/s	3953 ms	14K
Coding	C	Runs well	31.6 tok/s	6132 ms	26K
RAG	C	Runs well	26.7 tok/s	13176 ms	45K
Reasoning	C	Runs well	26.7 tok/s	8564 ms	26K

How Qwen3.5 27B (27B params) fits at each quantization level on Mac Studio M1 Ultra 64GB (46.1 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	10.5 GB	Low	D34
Q3_K_S	3	13.2 GB	Low	D36
NVFP4	4

HuggingFace

huggingface-cli download hf-unsloth--qwen3-5-27b-gguf

Upgrade options

RTX PRO 5000 Blackwell 48GBBudget pick

C68.5 tok/s decode

RTX 6000 Ada 48GBBiggest leap

C47.8 tok/s decode