Performance of mixed carbon nanotube bundle interconnects are analyzed for subthreshold circuits. As voltage scaling in ULSI ICs lead to performance challenges in delay, power dissipation and the overall performance of interconnects, we simulate two mixed CNT bundle configurations, MCB-1 and MCB-2, to analyze their propagation delay, power dissipated and energy delay product for 500μm interconnect length and at 20nm technology noce. Further, we do crosstalk analysis of the proposed bundles using a driver-interconnect-load model. One line is aggressor and another line is victim. Simulated results shows that MCB that has MWCNTs at the periphery and SWCNTs at the core is ideal for intermediate level interconnect applications.