MERGE3: Efficient Evolutionary Merging on Consumer-grade GPUs

Evolutionary model merging enables the creation of high-performing multi-task models but remains computationally prohibitive for consumer hardware. We introduce MERGE 3 , an efficient framework that makes evolutionary merging feasible on a single GPU by reducing fitness computation costs 50× while preserving performance. MERGE 3 achieves this by Extracting a reduced dataset for evaluation, Estimating model abilities using Item Response Theory (IRT), and Evolving optimal merges via IRT-based performance estimators. Our method enables state-of-the-art multilingual and cross-lingual merging, transferring knowledge across languages with significantly lower computational overhead. We provide theoretical guarantees and an open-source library 1 , democratizing high-quality model merging.