PCI Express is replacing PCI-X in high-performance systems, increasing the need for flexible PCI Express switching. PLX Technology's PEX 8548, a 48-port PCI Express switch, can handle a range of configurations from three x16 PCI Express ports. It's ideal for handling a pair of high-speed video cards in a setup that has an x8 host port plus three x8 ports and four x4 ports for extensive peripheral access. This third-generation device complies with PCI Express 1.1, including support for hot-swapping. It implements peer-to-peer transfers with a cut-through latency under 110 ns via a non-blocking switch architecture. Maximum payload size has been increased to 1 kbyte, suiting it for disk storage transfers. It supports advanced configuration, error reporting, and diagnostics via in-band and I2C out-of-band communication. Transmissions have end-to-end cyclic redundancy check (CRC) and poison bit support, which can lock out in-band configuration for additional security. The PEX 8548 comes in a 37.5- by 37.5-mm heat-slug ball-grid array package. Pricing starts at $65. The RDK development kit costs $1490.