DeepPrune: Parallel Scaling without Inter-trace Redundancy
Authors: name: Shangqing Tu, name: Yaxuan Li, name: Yushi Bai, name: Lei Hou, name: Juanzi Li
Organization: Knowledge Engineer Group @ Tsinghua University

Parallel scaling has emerged as a powerful paradigm to enhance reasoning
capabilities in large language models (LLMs) by generating multiple
Chain-of-Thought (CoT) traces simultaneously. However, this approach introduces
significant computational inefficiency due to inter-trace redundancy -- our
analysis reveals that over 80% of parallel reasoning traces yield identical
final answers, representing substantial wasted computation. To address this
critical efficiency bottleneck, we propose DeepPrune, a novel framework that
enables efficient parallel scaling through dynamic pruning. Our method features
a specialized judge model trained with focal loss and oversampling techniques
to accurately predict answer equivalence from partial reasoning traces which
realizes 0.87 AUROC on equivalence prediction, combined with an online greedy
clustering algorithm that dynamically prunes redundant paths while preserving
answer diversity. Comprehensive evaluations across three challenging benchmarks
(AIME 2024, AIME 2025, and GPQA) and multiple reasoning models demonstrate that
DeepPrune achieves remarkable token reduction by over 80% compared to
conventional consensus sampling on most cases, while maintaining competitive
accuracy within 3 percentage points. Our work establishes a new standard for
efficient parallel reasoning, making high-performance reasoning more efficient.
Our code and data are here: https://deepprune.github.io/