Switch Transformers: Scaling to Trillion Parameter Models with Simple and Efficient Sparsity
William Fedus, Barret Zoph, Noam Shazeer · J. Mach. Learn. Res. · 2021
Abstract
Simplifies mixture-of-experts routing to its limit by sending each token to exactly one expert rather than several, which cuts routing overhead and communication enough to make the approach practical at scale. Parameter count grows enormously while the compute spent per token stays fixed, along with the recipes needed to keep training stable.
Why it matters
The architecture behind most frontier models today, where a very large parameter count coexists with a modest per-token cost. Read it before the Kimi and DeepSeek reports here — it is the idea they are both building on.
https://arxiv.org/abs/2101.03961