Future opportunities for gigascale integration will be governed by a hierarchy of theoretical and practical limits that can be codified as follows: fundamental, material, device, circuit, and system. An exponential increase in on-chip integration is driving System-on-Chip (SoC) methodologies as a dominant design solution for gigascale ICs. Therefore, a second generation generic systems simulator (GENESYS) is developed to address a need for rapid assessment of technology/architecture tradeoffs for multi-billion transistor SoCs while maintaining the depth of core modeling codified in the hierarchy of limits. A newly developed system methodology incorporates a hiearchical block-based model, a dual interconnect distribution for both local and global interconnects, a generic on-chip bus model, and cell placement algorithms. A comparison of simulation results for five commercial SoC implementations shows increased accuracy in predicting die size, clock frequency, and total power dissipation. ITRS projections for future technology requirments are applied with results indicating that increasing static power dissipation is a key impediment to making continued improvements in chip performance. Additionally, simulations of a generic chip multi-processor architecture utilizing several interconnect schemes shows that the most promising candidate for the future of on-chip global interconnect networks will be hierarchical bus structures providing a high degree of connectivity while maintaining high operating frequencies.