CUDA: optimize MMQ int8 tensor core performance#8062
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JohannesGaessler merged 3 commits intoggml-org:masterfrom Jun 24, 2024
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CUDA: optimize MMQ int8 tensor core performance#8062JohannesGaessler merged 3 commits intoggml-org:masterfrom
JohannesGaessler merged 3 commits intoggml-org:masterfrom
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slaren
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slaren
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I see similar improvements with 3080 and 3090 Ti.
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MagnusS0
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* CUDA: optimize MMQ int8 tensor core performance * only a single get_mma_tile_x_k function * simplify code, make functions constexpr
Seunghhon
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* CUDA: optimize MMQ int8 tensor core performance * only a single get_mma_tile_x_k function * simplify code, make functions constexpr
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This PR adds the following optimizations for the CUDA MMQ kernels using int8 tensor cores:
ldmatrixPTX instruction to load data in blocks of 16 bytes instead of 4.Performance vs. master MMQ
Performance vs. master FP16 cuBLAS
I now consider the performance good enough that I think MMQ should be made the default again; the performance for small quants is still suboptimal but for those I think the memory savings outweigh the hit to speed. I would prefer to do the default change in a separate PR.