A Faster Generalized Two-Stage Approximate Top-K

ArXi:2506.04165v3 Announce Type: replace We consider the Top-$K$ selection problem, which aims to identify the largest $K$ elements in an array. Top-$K$ selection arises in many machine learning algorithms and often becomes a bottleneck on accelerators, which are optimized for dense matrix multiplications. To address this problem, Chern proposed a fast two-stage approximate Top-$K$ algorithm that: (i) partitions the input array into equal-sized chunks and selects the top-$1$ element from each partition; and (ii) sorts the resulting smaller subset and returns the top $K$ elements.