GLM-5.3 320B (18B active) Flash

User benchmarks GLM-5.3-Flash on two GB10 nodes (DGX Spark-class, 121 GiB unified memory each, tensor-parallel 2 over RoCE), comparing NVFP4 and EXL3 quantizations. Single-stream decode at 8k context is 30.1 tok/s for NVFP4 and 28.8 tok/s for EXL3. Setup uses vLLM with DFlash2 speculative decoding (k=7) and 8k context. NVFP4 collapses under concurrency (7.1 tok/s per stream at 4 streams) while EXL3 holds steady (26.7 tok/s). User reports NVFP4 prefills ~1.8x faster cold (1667.7 vs 925.9 tok/s at 8k) but has zero prefix cache hits, while EXL3 achieves 6.9x faster TTFT on reuse. Agent sessions are warm and concurrent, favoring EXL3. Later updates show k=3 recovers +87% for NVFP4 at C4, and TensorFold TP=2 pairs reach 113.2 tok/s structured single-stream.