MXFP4 with W4A8 kernels pushes Qwen3.8 27B to 280 tok/s on two Radeon R9700s.

A two-month follow-up on a dual R9700 setup: MXFP4 first reached parity with FP8, then passed it using W4A8 kernels, which the builder believes is the hardware limit for these cards (r/LocalLLaMA). BetterBench decode with DFlash2 runs 280.0 t/s on JSON down to 116.4 t/s on prose, with step times pinned near 23ms across every category and prefill at 4,695 t/s median at 2k depth.