User`s guide

13
Hardware Install
Hardware
Install
reCommended memory ConFigurations
The AMD Opteron processors have very specific memory module requirements, and due to
the design of the serverboard, there are certain configurations of memory that work best to
make the most effective use of the memory bandwidth.
The AMD Opteron features 128-bit DDR memory channels. DDR Memory Modules are only
64-bit. In order to benefit from the full bandwidth, you should always install the DIMMs in
pairs. The serverboard is designed to pair up DIMM slots 0/1 and slots 2/3 for the 128-bit
pathway.
The Opteron is designed with the Memory Controller Hub (MCH) built-in to the processor.
The DIMM Banks are thus controlled by the processor. If a processor is NOT present, then
the respective DIMM Bank is NOT recognized. When only one (1) processor is installed
in CPU0, only the H0 DIMM bank is active. DIMMs in the H1 DIMM Bank will NOT be
recognized.
The memory nodes are also shared over the entire bus. It is possible to operate a system
with two CPUs and only a pair of DIMMs in the H0 DIMM bank.
The Opteron does support 64-bit only operation, but due to the design of the DIMM banks,
the single DIMM must be inserted in either DIMM slot 0 or DIMM slot 2 to function. The
system will NOT boot otherwise.
The following is our recommended DIMM installation path based on the number of DIMMs
being installed (Remember to check that the DIMMS are 2.5V Registered ECC DDR
PC2100/PC2700/PC3200/DDR266/DDR333/DDR400 DIMMs and that they appear on the
List of Recommended Memory Modules):
IMPORTANT
* If you only have one (1) processor, install ALL DIMMs into the H0 DIMM Bank.
* To ensure compatibility, only use DIMM pairs of the same exact type and size
and made by the same company. Refer to “Appendix A: Recommended Memory
Modules” for a list of supported DIMMS.
1 DIMM H0 Bank: Slot 0 or Slot 2 (This only provides 64-bit memory access)
2 DIMMs H0 Bank: Slot 0, 1 or Slot 2, 3
4 DIMMs Single Processor H0 Bank: Slot 0, 1, 2, 3 *
Dual Processor H0 Bank: Slot 0, 1 or Slot 2, 3
H1 Bank: Slot 0, 1 or Slot 2, 3
6 DIMMs H0 Slot 0, 1, 2, 3 *
H1 Slot 0, 1
8 DIMMs H0 Slot 0, 1, 2, 3 *
H1 Slot 0, 1, 2, 3 *
* To support full speed of DDR400, please use [Single, Single, Single, Single] or
[Double, Double, Single, Single] or [Single, Single, Double, Double]. Besides, DDR400
is supported by CPU rev C0 and later.