What hardware runs Qwen3.5 4B?
Qwen3.5 4B is a 4.21B-parameter dense model (apache-2.0 license). Laptop-class. Strong retrieval and extraction for its size; don't ask it to architect your codebase.
All figures assume an f16 KV cache, a 0.6 GB display reserve on the GPU, and 64 GB of DDR5 system RAM for the offload tiers. Tune these in the calculator.
Minimum VRAM by quant and context
| Quant | File size | 8K | 16K | 32K | 64K | 128K |
|---|---|---|---|---|---|---|
| Q3_K_M * | 2.1 GB | 5 GB | 6.1 GB | 8.2 GB | 12.4 GB | 20.9 GB |
| Q4_K_M | 2.6 GB | 5.4 GB | 6.5 GB | 8.6 GB | 12.9 GB | 21.4 GB |
| Q5_K_M | 2.9 GB | 5.8 GB | 6.9 GB | 9 GB | 13.2 GB | 21.7 GB |
| Q6_K | 3.3 GB | 6.1 GB | 7.2 GB | 9.3 GB | 13.6 GB | 22.1 GB |
| Q8_0 | 4.2 GB | 7 GB | 8.1 GB | 10.2 GB | 14.5 GB | 23 GB |
| IQ4_XS | 2.3 GB | 5.2 GB | 6.2 GB | 8.4 GB | 12.6 GB | 21.1 GB |
Full-GPU figures: weights + f16 KV cache + overhead. * below our recommended floor of Q4_K_M.
GPU compatibility
Fits on GPUExpert offloadPartial offloadCPU only
Quant guidance
Our floor for Qwen3.5 4B is Q4_K_M — below that, quality degrades faster than the VRAM savings are worth. Prefer the highest quant that still lands "Fits on GPU" at your context length in the table above.
Recommended run command
Q4_K_M at 32K on a NVIDIA GeForce RTX 3080 10GB-class GPU (Fits on GPU):
llama-server -m Qwen3.5-4B-Q4_K_M.gguf -c 32768 --flash-attn -ngl 99
Frequently asked questions
How much VRAM does Qwen3.5 4B need?
At Q4_K_M and 32K context, Qwen3.5 4B needs about 8.6 GB of VRAM to run fully on GPU (weights + KV cache + overhead).
What is the smallest GPU that can run Qwen3.5 4B?
The NVIDIA GeForce RTX 3080 10GB (10 GB) is the smallest GPU in our set that runs Qwen3.5 4B well at 32K context.
What quantization should I use for Qwen3.5 4B?
We recommend Q4_K_M or higher. Q4_K_M weighs 2.6 GB (5.21 bits/weight); going below Q4_K_M costs noticeable quality on a model this size.
How long a context can Qwen3.5 4B handle?
Qwen3.5 4B supports up to 256K tokens. KV cache grows linearly with context.
Can I run Qwen3.5 4B without a GPU?
Yes, at reduced speed: on CPU with 64 GB of DDR5 it manages roughly 11 tokens/sec at 8K context (Q8_0).