Qwen3.5 4B needs ~4.6 GB VRAM. RX 580 8GB has 8.0 GB. With Q4_K_M quantization, expect ~45 tok/s.
Operating mode
Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.
Current mode
Balanced
Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.
Select quantization to explore
Fit status
Runs well
Decode
45.1 tok/s
TTFT
4291 ms
Safe context
132K
Memory
4.6 GB / 8.0 GB
This setup is broadly balanced for this model.
Older PCIe generation
PCIe 3.0 is workable, but it compounds the penalty when you offload heavily or try to scale across multiple cards.
| Workload | Grade | Fit | Decode | TTFT | Context |
|---|---|---|---|---|---|
| Chat | C | Runs well | 45.1 tok/s | 2341 ms | 132K |
| Coding | C | Runs well | 45.1 tok/s | 4291 ms | 132K |
| Agentic Coding | C | Runs well | 45.1 tok/s | 6242 ms | 132K |
| Reasoning | C | Runs well | 45.1 tok/s | 5072 ms | 132K |
| RAG | C | Runs well | 45.1 tok/s | 7802 ms | 132K |
How Qwen3.5 4B (4B params) fits at each quantization level on RX 580 8GB (8.0 GB usable).
| Quant | Bits | VRAM | Quality | Fit |
|---|---|---|---|---|
Q2_K | 2 | 1.6 GB | Low | C51 |
Q3_K_S | 3 | 2.0 GB | Low | C52 |
NVFP4 | 4 | 2.2 GB | Medium | C52 |
Q4_K_M | 4 | 2.4 GB | Medium | C53 |
Q5_K_M | 5 | 2.9 GB | High | C54 |
Q6_K | 6 | 3.3 GB | High | C54 |
Q8_0Best for your GPU | 8 | 4.3 GB | Very High | C53 |
F16 | 16 | 8.2 GB | Maximum | F0 |
Copy-paste commands to run Qwen3.5 4B on your machine.
Run
lms load hf-unsloth--qwen3-5-4b-gguf && lms server startYes, RX 580 8GB can run Qwen3.5 4B with a C grade (Runs well). Expected decode speed: 45.1 tok/s.
Qwen3.5 4B (4B parameters) requires approximately 4.6 GB of memory with Q4_K_M quantization.
The recommended quantization for Qwen3.5 4B is Q4_K_M, which balances quality and memory efficiency.
On RX 580 8GB, Qwen3.5 4B achieves approximately 45.1 tokens per second decode speed with a time-to-first-token of 4291ms using Q4_K_M quantization.
For coding workloads, Qwen3.5 4B on RX 580 8GB receives a C grade with 45.1 tok/s and 132K context.
On RX 580 8GB, Qwen3.5 4B can safely use up to 132K tokens of context. The model's official context limit is —, but available memory constrains the safe maximum.
Paste this snippet into any page to show a live fit card.
<iframe src="https://willitrunai.com/embed/hf-unsloth--qwen3-5-4b-gguf-on-rx-580-8gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>
Preview: