How to Speed Up Transformer Training Using NVIDIA Apex (FusedAdam, FusedLayerNorm) and Native torch.amp

TL;DR AI
2 min readKey summary
The article benchmarks NVIDIA Apex fused optimizers and normalization layers against standard PyTorch in Transformer training.
It walks through setting up a CUDA GPU environment, building Apex with extensions, and checking which fused kernels are actually available.
Results compare FusedAdam, FusedLayerNorm, and FusedRMSNorm against non-fused PyTorch equivalents to measure throughput gains.
It also contrasts legacy apex.amp with native torch.amp to show the practical mixed-precision path for faster training.
The main takeaway is to verify your Apex install before relying on fused kernels, so you avoid false performance assumptions.
