Intel integrated server RAID signifies unique system boards that are designed to add value above that of a standard RAID add-in card to Intel server boards and systems. BATTERY backup units (BBU) and maintenance-free backup units (mfbu) are available for hardware RAID products with embedded cache. Intel RAID expander cards are intended for any system with more than 8 drives. Several upgrade features can be added to enhance the performance and data protection of Intel intelligent RAID cards and modules.