Sliding-window attention looks like it beats linear attention. Only on short answers.
AspireAI community · Hugging Face blog (sirluk / iondy)
**Sliding-window attention looks like it beats linear attention. Only on short answers.**
A recent distillation run says the win flips once the model has to write a long answer. The team distilled Qwen3-4B-Instruct into four students that all hold the same 576 tokens of cache per attention layer, so the comparison is memory-matched rather than parameter-matched.
The architecture they call Bifocal splits that budget: a 448-token sliding window plus a compressed linear state, blended by a per-head data-dependent gate, with a learned sink instead of pinned tokens. On short-answer benchmarks the plain window wins by 0.7 to 1.5 points, matching the original sliding-window paper's claim. On hard math, where answers run to roughly 7,600 tokens, Bifocal averages 15.5 percent against 13.8, and on the 96 longest problems it solves 1.8 times as many as the window alone.
The honest limit: the overall math gap sits at the edge of statistical significance, and this is one team's own distillation run.
https://huggingface.co/blog/sirluk/sliding-window-beats-linear-attention
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