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nastya236
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Sep 15, 2026
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Thank you for the pull request! Great improvements! I left some comments and questions. |
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nastya236
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Sep 21, 2026
| bool can_use_qmv = supports(supports_qmv) || can_use_fp_gather_qmv; | ||
| // fp_gather_qmv wins at any batch size, gather_qmv only under 8 rows. | ||
| bool prefer_qmv = can_use_fp_gather_qmv || (can_use_qmv && M * B < 8); | ||
| auto call_qmm_sm80 = [&]() { |
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If at any batch size, why M * B < 8 not M < 8?
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Sorry, that comment was misleading. I've removed it. The existing logic (M * B < 8) still holds based on my benchmarking tests - the old gather_qmv kernel loses to the tile kernel as soon as there are more than a few rows.
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This speeds up gather_qmm on CUDA for MoE models.
mlx-lm benchmark examples with gemma4 26b and Nemotron 3 Nano 30B (p2048/g128)
Generation speed unchanged.
Note: this carries a few lines from #4507 but is otherwise independent of the global scale work so these can merge in either order.