The class of server hardware hosting the simulator is one of the he key factors in Second Life performance. Non-server items contributing to perceived poor performance are still in high quantity, but server class versus server utilization is a pretty consistent factor.

Each class of server representing a certain basic equipment and operating system specification has a numerical designation. Since some estate owners have opted not to upgrade to a newer class of hardware in order to avoid higher monthly, now it is the end of the server class system.