bfloat16 (BF16) is a 16-bit floating-point format that uses 1 sign bit, 8 exponent bits, and 7 mantissa bits. It extends FP16’s dynamic range while reducing precision. section 6.1
BF16 reduces memory use and generally preserves deep-learning performance, although lower precision can affect some calculations. Models trained in BF16 typically match FP16 mixed precision for inference performance and memory use. section 6.1 section 6.5
Practical considerations:
- Use BF16 on supported Google TPUs or NVIDIA Ampere GPUs; check NVIDIA support with torch.cuda.is_bf16_supported(). section 6.1
- Prefer BF16 when wider dynamic range matters more than FP16’s additional mantissa precision. section 6.1


