The next-generation Route Switch Processor (RSP4) provides improved performance on Cisco 7500 series routers. The RSP4 uses a 200-MHz R5000 processor with twice the primary cache and a 512-KB secondary cache to greatly improve performance. The biggest increases in performance are in process-level switching and other process-level tasks (for example, route calculations) where the RSP4 is between two and four times faster than an RSP2. Fast-switching performance is also improved. The RSP4 supports the high system availability (HSA) feature and can be used in combination with an RSP2 or another RSP4.