Quantizing training to MXFP8 with stochastic rounding: the accuracy-speed sweet spot

snowclipsed · x · 2026-11-14

Discussion of a training quantization scheme: stochastically quantize weights and activations to MXFP8 and compute gradients with MXFP8 matrix multiplications, claimed as the best accuracy-vs-speed tradeoff — an mxfp8-like SR method. The attached diagram lays out the full pipeline: BF16 activations quantized per-token to NVFP4 (4/6) for the forward GEMM, FP32 master weights quantized per-expert to NVFP4, while gradient paths (DGRAD/WGRAD) use MXFP8 with stochastic rounding, with FP32/BF16/MXFP8/NVFP4 precision boundaries marked. The poster wonders where the fusion boundaries should sit.

Related event: MoE Training Communication Slashed via 8-bit Quantization and Fused Kernels(4 posts)→

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