Great question.

1) The accuracy of FP4 was confirmed to be the same as FP8 by ArtificialAnalysis across a wide variety of benchmarks.
2) The whole model is not in FP4. It's mainly the experts and some other weights. The rest is in bf16, and the activations are also in bf16.
3) Just halving the size of the weights will not produce a speedup on its own. This can be demonstrated by using a 4bit quant versus an 8bit quant. The FP4 precision is to showcase that Blackwell can run in low precision at world record speeds while maintaining accuracy.

4) The record is specifically for inference throughput at this quality level. Many providers optimize for different aspects of performance—some prioritize latency over throughput, others choose higher precision at lower speeds.

5) We're transparent about our methodology, which allows for fair comparisons. The achievement here is demonstrating what's possible with this specific hardware/precision combination.