51Upgrading the system memorySystem memory interfaceThe system has eighteen DIMM slots. Each CPU controls nine slots. TheDIMM slots support DDR3-1333 registered/unbuffered ECC memorymodules. For single rank and dual rank RDIMM, a maximum 3 DIMMsper channel and a total 18 DIMMs can be supported. For UDIMMs andquad rank RDIMMs, only 2 DIMMs per channel are supported andmaximum total 12 DIMMs.• Each CPU has three memory channels (channel 1, 2 and 3).• Each channel has 3 slots.To maximize the memory performance, the DIMM modules should beinstalled as balanced as possible among processors and memorychannels. And slots with the same slot number across memory channelsshould be populated with identical DIMM.Independent ModeIndependent mode single processor configuration:Notes: 1. Place DIMMs in “X” location.2. DIMM population must correspond to the above tables.Channel 1DIMM slotsChannel 2DIMM slotsChannel 3DIMM slots NotesConfiguration 1C 1B 1A 2C 2B 2A 3C 3B 3AA XB X XC X X XD X X X XE X X X X X XF X X X X X X X X X SR, DR RDIMMSONLY