Sun Oracle Sun Fire X4270 M2 Service Manual page 92

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7. For maximum performance, apply the following rules:
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4-6 Sun Fire X4270 M2 Server Service Manual • May 2011
Populate QR DIMMs first, followed by SR or DR DIMMs.
Populate QR DIMMs in blue sockets (D8/D5/D2) first then white sockets
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(D7/D4/D1). See
Note that QR DIMMs are supported only in white sockets if adjacent blue
socket contains a QR DIMM.
Populate QR, SR, or DR DIMMs in sets of three for each CPU, one per
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memory channel. See
The best performance is ensured by preserving symmetry. For example: adding
3x of same kind of DIMMs, one per memory channel; and, if the server has two
CPUs, 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
Memory Considerations and Limitations
TABLE 4-2
1 DIMMs are available in two speeds: 1066 MHz and 1333 MHz
2 DIMM speed rules are as follows:
• 3x of the same kind of DIMMs per channel = 800 MHz
• 2x of the same kind of DIMMs per channel = 1333 MHz (for single-rank and
dual-rank DIMMs) or = 800 MHz (for quad-rank DIMMs)
• 1x of the same kind of DIMMs per channel = 1333 MHz (if using 1333 MHz
*
DIMMs)
• 1x of the same kind of DIMMs per channel = 1066 MHz (if using 1066 MHz
DIMMs)
3 The system operates all memory only as fast as the slowest DIMM configuration.
* This DIMM configuration requires CPUs supporting 1333 MHz.
.
FIGURE 4-2
.
FIGURE 4-2
for further details.
TABLE 4-2