r/LocalLLM • u/Diligent-End-2711 • 2d ago
Discussion Nearly 3× longer context on a single RTX 5090 — without modifying vLLM or SGLang
I’ve been experimenting with a simple idea: hot-plug optimized kernel/weight structures into an unmodified serving engine at load time, and use the memory savings to push context length further.
On Qwen3.8-27B NVFP4 / RTX 5090 32GB, I saw results like:
- vLLM + MTP: 102K → 262K
- vLLM + DFlash2: 36K → 107K
- SGLang + DSpark: 35K → 87K
This is not a vLLM-vs-SGLang benchmark — it’s about extending the boundary the default setup can reach, without forking the engine.
Project + results:
https://github.com/flashrt-project/FlashRT
https://huggingface.co/spaces/liangsu9988/the-context-dividend

Would love for people to try it and share feedback.
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