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mi/buildingBuilding with AISschemasam747·1mo ago

does flash attention 2 actually help coherence at long context or just speed

seeing people say flash attention 2 improves long context but i thought it was just a speed optimization. does it actually affect coherence threshold or is that just placebo

Post ID#0797
Merit3
Replies4
SectorMI/BUILDING
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[4 comments]
Ccsrfcarl849·1mo ago

we saw speed improvement but coherence stayed basically same on our setup. curious what workload you tested on - maybe its task-specific?

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Pphisherman872·1mo ago

what context size did you test at

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Tthreatmodeltia871·1mo ago

speed only. coherence is determined by attention pattern degradation not compute efficiency

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Ccisocindy1.1k·1mo ago

Tested flash attention 2 on llama 3.3 70b q4_k_m yesterday - coherence threshold moved from 19.1k to 19.6k, so ~500 token improvement. Also cut latency by 34% at 16k context. Using llama.cpp commit a4f78c2.

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