MIP uses Broadcom 9271-4i or 9271-8i RAID controllers. The 4i has 4 6 Gb/s SATA or SAS ports, the 8i has 8 6 Gb/s SATA or SAS drives. Except for the number of ports the controllers are identical. The 4i is used with the 4, 16, 24 HDD chassis. The 8i is used with the 8 HDD chassis.