Interfaces
Intel
®
Core
TM
i7-620LE/UE, i7-610E, i5-520E and Intel
®
Celeron
®
Processor P4500, P4505 Series
Datasheet Addendum
April 2010
18
Document Number: 323178-002
This mode is used when Intel
®
Flex Memory Technology is disabled and both Channel A
and Channel B DIMM connectors are populated in any order with the total amount of
memory in each channel being different.
2.1.4
Rules for Populating Memory Slots
In all modes, the frequency of system memory is the lowest frequency of all memory
modules placed in the system, as determined through the SPD registers on the
memory modules. The system memory controller supports only one DIMM connector
per channel.For dual-channel modes both channels must have an DIMM connector
populated and for single-channel mode only a single-channel must have an DIMM
connector populated.
2.1.5
Technology Enhancements of Intel
®
Fast Memory Access
(Intel
®
FMA)
The following sections describe the Just-in-Time Scheduling, Command Overlap, and
Out-of-Order Scheduling Intel
®
FMA technology enhancements.
2.1.5.1
Just-in-Time Command Scheduling
The memory controller has an advanced command scheduler where all pending
requests are examined simultaneously to determine the most efficient request to be
issued next. The most efficient request is picked from all pending requests and issued
to system memory Just-in-Time to make optimal use of Command Overlapping. Thus,
instead of having all memory access requests go individually through an arbitration
mechanism forcing requests to be executed one at a time, they can be started without
Figure 3.
Dual-Channel Symmetric (Interleaved) and Dual-Channel Asymmetric Modes
CH. B
CH. A
CH. B
CH. A
CH. B
CH. A
CL
0
Top of
Memory
CL
0
CH. A
CH. B
CH.B-top
DRB
Dual Channel Interleaved
(memory sizes must match)
Dual Channel Asymmetric
(memory sizes can differ)
Top of
Memory