DIMMs come in a variety of ranks: single, dual, or quad. Each DIMM is shipped with a label identifying its rank classification. The following table identifies the corresponding rank classification label shipped with each DIMM
Table 22 DIMM Rank Classifications Labels
Note - While Sun Server X3-2 does support single-rank DIMMs, that is, single-rank DIMMs can be installed in the server, Oracle does not offer any single-rank DIMMs for purchase, either as factory-installed options or as separately orderable options.