makeMoE: Implement a Sparse Mixture of Experts Language Model from Scratch
Blog post from HuggingFace
Avinash Sooriyarachchi's blog post provides an in-depth guide on implementing a Sparse Mixture of Experts (MoE) language model from scratch, drawing inspiration from Andrej Karpathy's 'makemore' project. The model architecture discussed utilizes a sparse mixture of experts, a departure from a solitary feed-forward neural net, to enhance training efficiency and inference speed. Key to the implementation are elements like top-k and noisy top-k gating for load balancing, Kaiming He initialization, and causal self-attention mechanisms. The blog emphasizes that while much of the architecture shares components with traditional transformers, sparse MoE models face unique challenges, such as training stability and deployment issues due to large parameter counts. The tutorial is designed to be hackable, allowing for experimentation with different neural net initialization strategies, tokenization methods, and hyperparameter searches, offering a comprehensive foundation for understanding and building sparse MoE models.