Service Manual

System Overview 1-7
System Memory
System memory resides on a memory module card and consists of a mini-
mum of 128 MB of 72-bit buffered EDO memory. Memory can be expanded
up to 4 GB by installing combinations of 32-, 128-, and 256-MB buffered EDO
DIMMs on the memory module.
NOTE: DIMMs must be rated at 50 or 60 ns. With a mixture of 50- and 60-ns
DIMMs, system memory will run at 60 ns.
The memory module provides 16 168-pin DIMM sockets divided into four
banks, each consisting of four sockets labeled “DIMM A” through “DIMM D”
(see Figure 1-6). Memory upgrade guidelines are as follows:
• DIMMs must be installed one bank (four DIMMs) at a time, starting with
bank 1 and working toward bank 4. There should be no open banks
between populated banks.
• Within a bank, install DIMMs in the following order: DIMM A, DIMM B,
DIMM C, and DIMM D.
• DIMM sizes cannot be mixed within a memory bank. However, one mem-
ory bank can hold different-size DIMMs from another memory bank.
• Of the DIMMs to be installed in the system, install the size you have the
most of in the lowest-numbered bank(s), the less numerous size in the
next banks, and least numerous size in the highest-numbered banks being
used. For example, when installing four 256-MB DIMMs, eight 128-MB
DIMMs, and four 32-MB DIMMs, install the 128-MB DIMMs in banks 1
and 2. The 256- and 32-MB DIMMs can be installed in banks 3 and 4; it
does not matter which bank holds which size.
Figure 1-6. Memory Module
For more detailed information about DIMM installation guidelines and samples
of DIMM configurations, see “Adding Memory” in Chapter 8 of the Dell
PowerEdge 6300 Systems Installation and Troubleshooting Guide.
bank 1
bank 4
DIMM D socket
bank 3
bank 2
bank 1
bank 4
bank 3
bank 2
DIMM C socket
DIMM B socket
DIMM A socket