Can Sun Fire X4600 Server memory DIMMs be interchanged with the Sun Fire X4600 M2 Server memory DIMMS?
No. The two server series use different DIMMs. The Sun Fire X4600 Server uses DDR1/400 registered DIMMs while the Sun Fire X4600 M2 Server takes advantage of the Opteron Rev F CPU’s DDR2 memory controller and use DDR2/667 DIMMs. In all cases, the systems have 4 memory DIMM slots per CPU socket and the DIMMs need to be installed in pairs for 128-bit memory access. All DIMMs must be of the same speed and density on a processor board however different processor boards may run with a different set of density/speed DIMMs as long as they are qualified for that system. For the Sun Fire X4600 M2 servers, the 2 GB and 4GB DIMMs are dual ranked. If more than 4 dual ranked DIMMs are populated per CPU, DDR2 clocking drops from 667 MHz to 533MHz.
