1. newer optimizations algorithms converge faster (Adam, adagrad)
2. lower-precision numerics can be used (TF32 is 19bit, bf16 is popular)
3. matrix multiplications are implemented in hardware (tensor cores, AMX)
4. neural networks are compiled directly (TVM, halide)
5. multi-device network topologies are tuned for training (e.g. nvlink improvements)
6. companies employ grad-student descent (hire a bunch of PhDs and task them with improving MLPerf results)