AC82G41SLGQ3 Datasheet, PDF (527/604 Pages) Intel Corporation – Intel® 4 Series Chipset Family

Functional Description
13.2 System Memory Controller
Note:
The (G)MCH system memory controller supports both DDR2 and DDR3 protocols with
two independent 64 bit wide channels each accessing one or two DIMMs. The controller
supports a maximum of two non-ECC DDR2 DIMMs or two un-buffered non-ECC DDR3
DIMMs per channel; thus, allowing up to four device ranks per channel. Intel^® Fast
Memory Access (FMA) supported.
The 82G41 GMCH only supports 1 DIMM per channel. References to 2 DIMMs per
channel only apply to the 82Q45, 82Q43, 82B43, 82G45, 82G43 GMCH and 82P45,
82P43 MCH. The 82G43 supports 1 or 2 DIMMs per channel depending upon part.
13.2.1
System Memory Organization Modes
The system memory controller supports two memory organization modes: Single
Channel and Dual Channel.
13.2.1.1
Single Channel Mode
In this mode, all memory cycles are directed to a single channel.
Single channel mode is used when either Channel A or Channel B DIMMs are populated
in any order, but not both.
13.2.1.2 Dual Channel Modes
13.2.1.2.1
Dual Channel Symmetric Mode
This mode provides maximum performance on real applications. Addresses are ping-
ponged between the channels after each cache line (64 byte boundary). If there are
two requests, and the second request is to an address on the opposite channel from the
first, that request can be sent before data from the first request has returned. If two
consecutive cache lines are requested, both may be retrieved simultaneously, since
they are assured to be on opposite channels.
Dual channel symmetric mode is used when both Channel A and Channel B DIMMs are
populated in any order with the total amount of memory in each channel being the
same, but the DRAM device technology and width may vary from one channel to the
other.
Table 30 is a sample dual channel symmetric memory configuration showing the rank
organization.
Table 30.
Sample System Memory Dual Channel Symmetric Organization Mode
Rank
Channel 0
Population
Cumulative Top
Address in
Channel 0
Channel 1
Population
Cumulative Top
Address in
Channel 1
Rank 3
Rank 2
Rank 1
Rank 0
0 MB
256 MB
512 MB
512 MB
2560 MB
2560 MB
2048 MB
1024 MB
0 MB
256 MB
512 MB
512 MB
2560 MB
2560 MB
2048 MB
1024 MB
Datasheet
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