The Super Socket 7, also referred to as Super 7, is an extension of the Socket 7 ZIF socket specification. It features a 100 MHz front-side bus, support for AGP, and a SPGA package. Super Socket was used by AMD K6-2 and K6-III processors, some of the final Cyrix M-II processors, some of the final IDT WinChip 2 processors, and Rise mP6 processors. It is backward compatible with Socket 7, meaning a Socket 7 CPU can be used with a Super Socket 7 motherboard, but a Super Socket 7 CPU cannot operate at full speed in a Socket 7 motherboard. Socket 5 CPUs are pin-compatible with Super Socket 7, but not all motherboards designed for Super Socket 7 supported the voltages needed for Socket 5 CPUs. While AMD had previously always used Intel sockets for their processors, Socket 7 was the last one for which AMD retained legal rights. Intel had hoped by discontinuing Socket 7 development and moving to Slot 1 that AMD would be left with an outdated platform, making their processors non-competitive. By extending the FSB from 66 to 100 MHz, Super Socket 7 gave AMD the stopgap solution they needed while developing their own independent motherboard infrastructure, Slot A.