24 Chapter 1
The following conditions must be met:
TMatched DIMM configuration in each channel
TSame Density (128MB, 256MB, 512MB, etc.)
TSame DRAM technology (128Mb, 256Mb, or 512Mb)
TSame DRAM bus width (x8 or x16)
TBoth either single-sided or dual-sided
TMatched in both Channel A and Channel B memory channels
TPopulate symmetrical memory slots (Slot 0 or Slot 1)
The following conditions do not need to be met:
TSame brand
TSame timing specifications
TSame DDR speed
Symmetrical DIMMs must be identical for optimal performance
TSame DIMM density, e.g. 128MB, 256MB, 512MB, etc.
TSame DRAM Technology, e.g. 128M-bit, 256M-bit, etc.
TSame DRAM bus width, e.g. x8 or x16
TSingle Sided or Dual Sided
NOTE: Note: Memory interface speed will be set to lowest speed of memory populated
Memory Characteristics
Optimize performance for single or dual channel is obtained with matched DIMM population
Table below shows DIMMs with same Organization and Density, but are non-matching as bus width,
technology and/or external banks are different
TMixing these DIMMs will put platform into single channel mode
DIMM 1 DIMM 2 DIMM3 DIMM4 Tota l
128MB~1GB 128MB~1GB 256MB~2GB
128MB~1GB 128MB~1GB 256MB~2GB
128MB~1GB 128MB~1GB 128MB~1GB 128MB~1GB 512MB~4GB
1256Mb32Mx8 * 8 pcs256MB32Mx64
2128Mb16Mx8 * 16 pcs256MB32Mx64
1256Mb16Mx16 * 4 pcs128MB16Mx64
1128Mb16Mx8 * 8 pcs128MB16Mx64
External
Banks
TechnologyCompositionDensityOrganization
1256Mb32Mx8 * 8 pcs256MB32Mx64
2128Mb16Mx8 * 16 pcs256MB32Mx64
1256Mb16Mx16 * 4 pcs128MB16Mx64
1128Mb16Mx8 * 8 pcs128MB16Mx64
External
Banks
TechnologyCompositionDensityOrganization
Different Bus
Width
Different
Technology
Same
Density
Same
Organization
Same # of
DRAM Banks
Same
Bus Width
Different
Technology
Same
Density
Same
Organization
Different # of
DRAM Banks
Non-Matched
128MBDIMMs
Non-Matched
256MBDIMMs