As the process technology scales down to deep sub-micron and frequency of a high-performance processor increases beyond 300 MHz, coupling induced signal integrity problems become more severe. Ignoring coupling effects can lead to functional failures or speed degradation. As a result, the traditional approach of repeater insertion driven by propagation delay and slew rate optimization becomes inadequate. In this paper, we propose a design methodology to select optimal repeaters for high-performance processors by considering not only the delay and slew rate, but also crosstalk effects. A Concurrent Decision Diagram (CDD) is further suggested to achieve crosstalk constraints with various trade-offs.