Lecture 80: How FlashAttention 4 Works

Name: Lecture 80: How FlashAttention 4 Works
Uploaded: 2025-10-01
Duration: 4509 s
Channel: GPU MODE
Description: Charles Frye explains the FlashAttention 4 forward-pass implementation on Blackwell GPUs. This developer lecture predates the 2026 research paper and supplies implementation context, rather than a validation of that paper’s results.

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Charles Frye explains the FlashAttention 4 forward-pass implementation on Blackwell GPUs. This developer lecture predates the 2026 research paper and supplies implementation context, rather than a validation of that paper’s results. GPU MODE / Charles Frye

What to look for

Expensive GPUs can still spend time waiting on slower operations. Research from Together AI and five other organizations shows how better scheduling can turn more of that hardware into useful work.

Read the full analysis: FlashAttention-4: Faster chips still need better software ↗