Why Local LLMs Suddenly Slow Down at Long Context

This story was originally published on HackerNoon at: https://hackernoon.com/why-local-llms-suddenly-slow-down-at-long-context. Your local LLM runs fine until it doesn't. A look at KV cache spilling from VRAM into shared memory, and why it happens silently on Windows. Check more stories related to tech-stories at: https://hackernoon.com/c/tech-stories. You can also check exclusive content about #local-llms, #llama.cpp, #kv-cache, #vram, #gpu, #local-inference, #machine-learning, #hackernoon-top-story, and more. This story was written by: @speederx. Learn more about this writer by checking @speederx's about page, and for more stories, please visit hackernoon.com. Your local LLM runs fine until the context fills up past a certain point - then generation speed can drop by ~50%. The cause is the KV cache spilling out of VRAM into slower shared memory. On Windows it happens silently, with no out-of-memory error to warn you.