NVIDIA / NVIDIA/TransformerEngine

Heuristic Fallback in cuDNN: Why THD Format Reverts to SM80 on Hopper GPUs

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Since Feb 3, 2026.

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Description

"Why does the forward pass call the cuDNN SM90 interface when the learnable_sink option is enabled with qkv_format="bshd", but reverts to the cuDNN SM80 interface when qkv_format="thd" is selected?"Image
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