— Clock meshes posses inherent low clock skews and excellent immunity to PVT variations, and have increasingly found their way to high-performance IC designs. However, analysis of such massively coupled networks is significantly hindered by the sheer size of the network and tight coupling between non-tree interconnects and large numbers of clock drivers. The presented Harmonic-weighted model order reduction algorithm is motivated by the key observation of the steadystate operation of the clock networks, and its efficiency is facilitated by the locality analysis via port sliding. The scalability of the analysis is significantly improved by eliminating the need of computing infeasible multi-port passive reduced order interconnect models with large port count. And the overall task is decomposed into tractable and naturally parallelizable model generation and FFT/Inverse-FFT operations, all on a per driver or per sink basis.