RMSNorm
Most modern language models, like Llama and Mistral, normalize activations with Root Mean Square Normalization (RMSNorm). Here is what it does, and a PyTorch module you can drop into a model.
The problem it solves
Inside a neural network, a layer’s output feeds the next layer as input. Those values can become too big or too small as they pass through layer after layer. A value that doubles at each of 40 layers is unusable by the end. Normalization rescales the values back to a steady range before they move on, so training stays stable.