11
CHAPTER
3
Troubleshooting DIMM Problems
This chapter describes how to detect and correct problems with the server’s Dual
Inline Memory Modules (DIMM)s. It includes the following sections:
■ “DIMM Population Rules” on page 11
■ “DIMM Replacement Policy” on page 12
■ “How DIMM Errors Are Handled by the System” on page 12
■ “Isolating and Correcting DIMM ECC Errors” on page 18
DIMM Population Rules
The DIMM population rules for the server are as follows:
■ Each CPU can support a maximum of eight DIMMs.
■ The DIMM slots are paired and the DIMMs must be installed in pairs (0-1, 2-3, 4-
5, and 6-7). See
FIGURE 3-1 and FIGURE 3-2. The memory sockets are colored black
or white to indicate which slots are paired by matching colors.
■ DIMMs are populated starting from the outside (away from the CPU) and
working toward the inside.
■ CPUs with only a single pair of DIMMs must have those DIMMs installed in that
CPU’s outside white DIMM slots (6 and 7). See
FIGURE 3-1 and FIGURE 3-2.
■ Only DDR2 800 Mhz, 667Mhz, and 533Mhz DIMMs are supported.
■ Each pair of DIMMs must be identical (same manufacturer, size, and speed).
