Functional Description
R
Intel
®
82925X/82925XE MCH Datasheet 177
10.3.1 DRAM Technologies and Organization
All standard 256-Mb, 512-Mb, and 1-Gb technologies and addressing are supported for x16 and
x8 devices.
• All supported DDR2 devices have 4 or 8 banks.
• The MCH supports various page sizes. Page size is individually selected for every rank.
• 4 KB, 8 KB, and 16 KB for asymmetric, interleaved, or single channel modes.
• The DRAM sub-system supports single or dual channels, 64b wide per channel for non-ECC
and 72b wide per channel with ECC (82925X MCH only).
• There can be a maximum of 4 ranks populated (2 Double Sided DIMMs) per channel.
• Mixed mode Double Sided DIMMs (x8 and x16 on the same DIMM) are not supported
• By using 1-Gb technology, the largest memory capacity is 8 GB
32M rows/bank * 4 banks/device * 8 columns * 8 devices/rank * 4 ranks/channel *
2 channel * 1b/(row*column) * 1G/1024M * 1B/8b = 8 GB.
Though it is possible to put 8 GB in system by stuffing both channels this way, the MCH is
still limited to 4 GB of addressable space due to the number of address pins on the FSB.
• By using 256Mb technology, the smallest memory capacity is 128 MB
(4M rows/bank * 4banks/device * 16 columns * 4 devices/rank * 1 rank * 1B/8b =128 MB)
• DDR2 533 with CAS latency timings of 3-3-3, unbuffered non-ECC x8 DIMMS are
supported at 1.9 V.
10.3.1.1 Rules for Populating DIMM Slots
• In all modes, the frequency of system memory will be the lowest frequency of all DIMMs in
the system, as determined through the SPD registers on the DIMMs.
• In the Single Channel mode, any DIMM slot within the channel may be populated in any
order. Either channel may be used. To save power, do not populate the unused channel.
• In Dual Channel Asymmetric mode, any DIMM slot may be populated in any order.
• In Dual Channel Interleaved mode, any DIMM slot may be populated in any order, but the
total memory in each channel must be the same.
To Next Page
Loading...
Need help?
General
