Sun Microsystems X6270 manual Dimm Rank Classification Labels

■Populate the DIMM slots for each memory channel that are the farthest from the CPU first.

For example, populate D8/D5/D2 first; then D7/D4/D1 second; and finally, D6/D3/D0. See FIGURE 2-3.

■Populate QR DIMMs first, followed by SR or DR DIMMs.

■Populate QR DIMMs in blue sockets (D8/D5/D2) first then white sockets (D7/D4/D1). See FIGURE 2-3.

Note that QR DIMMs are supported only in white sockets if adjacent blue socket contains a QR DIMM.

4.For maximum performance, apply the following rules:

■The best performance is ensured by preserving symmetry. For example, adding 3x of same kind DIMMs, one per memory channel, and ensuring that both CPUs have the same size of DIMMs populated in the same manner.

■In certain configurations, DIMMs will run slower than their individual maximum speed. See TABLE 2-2for further details.

TABLE 2-2DIMM Speed Considerations

1DIMMs are available in two speeds: 1066 MHz and 1333 MHz.

2DIMM speed rules are as follows:

■3x DIMM per channel = 800

■2x DIMM per channel = 1333 MHz (for single-rank and dual- rank DIMM or = 800 MHz (for quad-rank DIMMs)

■1x DIMM per channel = 1333 MHz (if using 1333 MHz DIMMs1)

■1x DIMM per channel = 1066 MHz (if using 1066 MHz DIMMs)

3The system operates all memory only as fast as the slowest DIMM configuration.

1This DIMM configuration requires CPUs supporting 1333 MHZ.

DIMM Rank Classification Labels

DIMMs come in a variety of ranks: single, dual, or quad. Each DIMM is shipped with a label identifying its rank classification.

TABLE 2-3identifies the corresponding rank classification label shipped with each DIMM.

Chapter 2 Install Server Module Optional Components 17