Intel® 945G/945GZ/945GC/ 945P/945PL Express Chipset Family ...

Functional Description
1-Gb technology
128-M cells x8 data bits/cell
1-K columns
8 banks
16-K rows
Each component has a 1-KB page.
One DIMM has 8 components resulting in an 8-KB page.
The capacity of one rank is 1 GB.
64-M cells x16 data bits/cell
1-K columns
8 banks
8-K rows
Each component has a 2-KB page.
One DIMM has 4 components resulting in an 8-KB page.
The capacity of one rank is 512MB.
The DRAM sub-system supports single or dual channels, 64b wide per channel. There can be a
maximum of 4 ranks populated (2 Double Sided DIMMs) per channel. Mixed mode DDR DS-
DIMMs (x8 and x16 on the same DIMM) are not supported (not validated)
By using 1Gb technology, the largest memory capacity is 8 GB (16K rows * 1K columns *
1 cell/(row * column) * 8 b/cell * 8 banks/device * 8 devices/rank * 4 ranks/channel *
2 channel *1M/(K*K) * 1G/1024M * 1B/8b = 8 GB). Using 8 GB of memory is only possible in
Interleaved mode with all ranks populated at maximum capacity. The Intel 82945G GMCH and
82894P MCH are limited to 4 GB of address space. Any memory in the system beyond 4 GB
cannot be addressed and should not be populated due to the additional loading it places on the
memory subsystem.
By using 256Mb technology, the smallest memory capacity is 128 MB (8K rows * 512 columns *
1 cell/(row * column) * 16b/cell * 4 banks/device * 4 devices/rank * 1 rank * 1M/1024K * 1B/8b
= 128 MB)
10.2.2.1 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.
228 Intel ® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet