NVIDIA / NVIDIA/CUDALibrarySamples
cuSPARSELt FP4 Issue on RTX 5090
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@j4yan is already working on this.
Since Jun 11, 2025.
cuSPARSELt
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Description
I'm trying to achieve "3352 Effective AI TOPS / TFLOPS using the Sparsity Feature" on 5090.
My code (matmul_fp4.cpp.txt) is based on the cuSPARSELt example 1, it works good on FP16, INT8 and FP8, but not FP4.
with m=n=k=32, cusparseLtMatmul failed with internal error (7) matmul_fp4-5.log
with m=n=k>=64, cusparseLtMatmulSearch failed with internal error (7) matmul_fp4-6.log
and it is interesting that compressed_size is actually bigger than A_size.
Where am I wrong?
P.S. nvidia-smi.log
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