Figure 31. Installing Memory - IBM @server xSeries 343 Product Manual

Certain combinations of DIMM types in the same system can violate the Write Ringback
measurement specification during analog validation.
•
When mixing double-ranked DIMMs (x4 or x8) with single-ranked DIMMs (x4 or x8), if a single-
ranked DIMM is placed in the populated slot closest to the MCH, the Write Ringback at that
DIMM violates the JEDEC DRAM specification.
The baseboard's signal integrity and cooling are optimized when memory banks are populated in
order. Therefore, when installing memory, DIMMs should be installed starting with Bank 1 and
ending with Bank 3.
DIMM and memory configurations must adhere to the following:
•
DDR266 registered ECC DIMM modules
•
DIMM organization: x72 ECC
•
Pin count: 184
•
DIMM capacity: 128 MB, 256 MB, 512 MB, 1 GB, 2 GB
•
Serial PD: JEDEC Rev 2.0
•
Voltage options: 2.5 V (VDD/VDDQ)
•
Interface: SSTL2
•
Two DIMMs must be populated in a bank for a x144 wide memory data path.
•
Any or all memory banks may be populated.
98
1B 2B 3B
1A 2A 3A

Figure 31. Installing Memory

TP123
Upgrading the Hardware