Can I run it?
Can I run Qwen3.8 27B on GeForce RTX 5090?
Tight fit
Tight fit fully on your GeForce RTX 5090 at UD-Q8_K_L, 8K context, about 34–47 tok/s. Weights 26.1 GB plus 0.57 GB of KV cache — 27.3 GB of 29.9 GB usable. Up to 32K context still fits.
Best quantUD-Q8_K_L
Working context8K
Max that fits32K
Speed34–47 tok/s
Weights26.1 GB
KV cache0.57 GB
Total27.3 GB
Usable29.9 GB
Qwen3.8 27B details · GeForce RTX 5090 page · How this estimate is made
Run commands
llama.cpp
llama-server -hf unsloth/Qwen3.8-27B-GGUF:UD-Q8_K_L -c 8192 -ngl 64
Ollama
ollama run qwen3.8
LM Studio
lms get unsloth/Qwen3.8-27B-GGUF # Then load quant UD-Q8_K_L
Assumptions
- Estimate, not a benchmark. Decode speed uses a memory-bandwidth model at 55–75% of peak.
- KV cache is FP16. Engine overhead assumes llama.cpp (0.3 GB + 1% of the weights). Ollama is closer to 0.9 GB + 3%, LM Studio closer to 1 GB + 3%.
- UD-Q8_K_L size is the real GGUF file size from Hugging Face.
- 0.5 GB is reserved because this GPU also drives a display, then 5% of the rest is left free.
- Speed is quoted at 8K context, not at the maximum context that still fits.
Larger models that also fit
- Can I run Qwen3.6 35B A3B on GeForce RTX 5090? — Tight fit, UD-Q6_K, 364–497 tok/s
- Can I run Qwen3.8 35B A3B Distill on GeForce RTX 5090? — Tight fit, Q6_K, 374–510 tok/s
- Can I run Qwen2.5 32B Instruct on GeForce RTX 5090? — Runs, Q5_K_M, 39–53 tok/s
Updated 2026-10-17. Profile on this page is the device default plus 32 GB of DDR5-5600 system RAM.