Alternate direction method of multipliers (ADMM) technique has re- cently been proposed for LDPC decoding. Even though it improves the error rate performance compared with traditional message pass- ing (MP) techniques, it shows a higher computation complexity. In this article, the ADMM decoding algorithm is first described. Then, its computation complexity is analyzed. Finally, an optimized ver- sion which benefits from the multi-core processors architecture as well as the ADMM algorithm’s parallelism is presented. The opti- mized version of the ADMM decoder can achieve up to 30 Mbps for standardized LDPC codes on a laptop x86 processor. Therefore, it could guide an efficient GPU implementation for real-time and high- throughput decoding systems requiring correction performances be- yond MP-Sum Product Algorithm (SPA) capabilities.