HomeCan I run it?Qwen3-8BQwen3-8B on an RTX 4090
Yes. Qwen3-8B at FP16 needs about 19.8 GB, and the GeForce RTX 4090 has 24.0 GB usable at a ~4k context.
Can I run Qwen3-8B on an RTX 4090?
Qwen3-8B at FP16 needs about 19.8 GB, and the GeForce RTX 4090 has 24.0 GB usable. That figure is 24 GB of VRAM on the spec sheet, of which 24.0 GB is usable for weights and cache, at 1008 GB/s memory bandwidth. Alibaba’s 8B Qwen3. A strong small dense model, and a common upgrade from older 7B–8B weights. These are estimates from our formula, not measured benchmarks.
- Quant that fits
- FP16 Fits with headroom
- Memory needed
- 19.8 GB at FP16, ~4k context
- Usable VRAM
- 24.0 GB of 24 GB VRAM
- Est. tokens/sec
- 37–52 estimate
Memory at each quant
| Quant | Need vs 24.0 GB | Verdict |
|---|---|---|
| Q4_K_M | 6.7 GB | Q4Fits |
| Q8_0 | 11.0 GB | Q8Fits |
| FP16 | 19.8 GB | FP16Fits |
Estimated tokens per second
Estimate: 37–52 tokens/sec at FP16. This is a bandwidth-derived range, not a bench. Efficiency is a 60–85% GPU band from How we calculate.
Context headroom
At FP16, this machine has headroom out to about 16k tokens under our KV estimate. Longer chats need more memory for the cache. Figures assume an FP16 KV cache.
| Context | KV cache (FP16) | Total at FP16 | Verdict |
|---|---|---|---|
| 4k | 0.6 GB | 19.8 GB | Fits |
| 8k | 1.2 GB | 20.4 GB | Fits |
| 16k | 2.4 GB | 21.7 GB | Tight |
| 32k | 4.8 GB | 24.1 GB | Won’t fit |
| 64k | 9.7 GB | 28.9 GB | Won’t fit |
| 128k | 19.3 GB | 38.6 GB | Won’t fit |
What to do instead
- See the best GPU for this model family and the Qwen3-8B model page.
Other hardware for Qwen3-8B
- Qwen3-8B on an RTX 3060 12GBTight
- Qwen3-8B on an RTX 3070 TiFits
- Qwen3-8B on an RTX 3080Fits
- Qwen3-8B on an RTX 4060 Ti 16GBFits
- Qwen3-8B on an RTX 4070 Ti SuperFits
- Qwen3-8B on an RTX 5070 TiFits
Other models on an RTX 4090
- Qwen3-32B on an RTX 4090Tight
- Qwen3-30B-A3B on an RTX 4090Tight
- Qwen3.8-27B on an RTX 4090Fits
- Gemma 3 27B on an RTX 4090Fits
- Gemma 4 31B on an RTX 4090Tight
- gpt-oss-20b on an RTX 4090Fits
Quick answers
- Can I run Qwen3-8B on an RTX 4090?
- Yes. Qwen3-8B at FP16 needs about 19.8 GB, and the GeForce RTX 4090 has 24.0 GB usable.
- How much VRAM does Qwen3-8B need?
- About 6.7 GB at Q4_K_M, 11.0 GB at Q8_0 and 19.8 GB at FP16, estimated for a ~4k context.
- How fast is Qwen3-8B on an RTX 4090?
- Our estimate is 37–52 tokens per second at FP16. It is not a measured benchmark.
- What context length can I use?
- At FP16, our KV estimate supports up to about 16k tokens before the cache pushes the total over usable memory.