Modal Details How to Run RL Samplers on Mixed-Precision, Mixed-Accelerator Hardware

lmoroney · x · 2026-10-15

Modal researcher Nan Jiang's blog 'Toward RL on mixed-precision, mixed-accelerator samplers' explores decoupling samplers from the trainer: since sampling takes 80–85% of GPUs in large RL runs, they run samplers on six accelerator types with their own kernels and precisions (FP8, MXFP4, NVFP4) feeding one BF16 B200 trainer, addressing the learning and stability problems introduced by training–inference mismatch.

Related event: Modal demonstrates stable, cheaper RL training on mixed-precision, mixed-accelerator clusters(7 posts)→

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