Sebastian Raschka Breaks Down GLM-5.2's IndexShare for Cheaper 1M-Token Sparse Attention

Ahead of AI (Sebastian Raschka)·low signal

In a June 18 'Ahead of AI' model note, Sebastian Raschka dissects GLM-5.2's IndexShare mechanism for cheaper 1M-token sparse (DSA) attention — the key efficiency lever behind the open-weight model's long-context inference. For builders weighing self-hosting a frontier-class coding model, the analysis explains how IndexShare keeps long-context costs down, i.e., the architectural 'why' behind GLM-5.2's pricing, from a high-signal source rather than vendor marketing. Useful before committing GPU budget to long-context self-hosting.