How long has the Xeon processor been in use for?
Xeon
June 1998
Xeon (/ˈziːɒn/ ZEE-on) is a brand of x86 microprocessors designed, manufactured, and marketed by Intel, targeted at the non-consumer workstation, server, and embedded system markets. It was introduced in June 1998.  Xeon processors are based on the same architecture as regular desktop-grade CPUs, but have some advanced features such as support for ECC memory, higher core counts, support for larger amounts of RAM, larger cache memory and extra provision for enterprise-grade reliability, availability and serviceability features responsible for handling hardware exceptions through the Machine Check Architecture. They are often capable of safely continuing execution where a normal processor cannot due to these extra RAS features, depending on the type and severity of the Machine Check Exception. Some also support multi-socket systems with two, four, or eight sockets through use of the Quick Path Interconnect bus.