Pi 5 Overview The Raspberry Pi 5 model B preserves the credit-card-sized footprint of the previous generations, but crams a bit more functionality into the tiny space, including an RTC, a power button, a separate UART header, a 4-pin fan connector, a PCI Express FPC connector, two dual-purpose CSI/DSI FPC connectors, and four independent USB buses (one to each of the 2x USB 3.0 ports and 2x USB 2.