Flex Memory Technology Operation - Intel I5-520E - DATASHEET ADDENDUM Datasheet

Interfaces
2.1.3.2 Dual-Channel Mode - Intel
The IMC supports Intel
advantages of the Dual-Channel Symmetric (Interleaved) and Dual-Channel
Asymmetric Modes. Memory is divided into a symmetric and a asymmetric zone. The
symmetric zone starts at the lowest address in each channel and is contiguous until the
asymmetric zone begins or until the top address of the channel with the smaller
capacity is reached. In this mode, the system runs with one zone of dual-channel mode
and one zone of single-channel mode, simultaneously, across the whole memory array.
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Figure 2. Intel

Flex Memory Technology Operation

2.1.3.2.1 Dual-Channel Symmetric Mode
Dual-Channel Symmetric mode, also known as interleaved mode, provides maximum
performance on real world 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 ensured to be on
opposite channels. Use Dual-Channel Symmetric mode when both Channel A and
Channel B DIMM connectors are populated in any order, with the total amount of
memory in each channel being the same.
When both channels are populated with the same memory capacity and the boundary
between the dual channel zone and the single channel zone is the top of memory, IMC
operates completely in Dual-Channel Symmetric mode.
Note: The DRAM device technology and width may vary from one channel to the other.
2.1.3.2.2 Dual-Channel Asymmetric Mode
This mode trades performance for system design flexibility. Unlike the previous mode,
addresses start at the bottom of Channel B and stay there until the end of the highest
rank in Channel B, and then addresses continue from the bottom of Channel A to the
top. Real world applications are unlikely to make requests that alternate between
addresses that sit on opposite channels with this memory organization, so in most
cases, bandwidth is limited to a single channel.
April 2010
Document Number: 323178-002
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Flex Memory Technology Mode. This mode combines the
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C H A C H B
C
B B
C H A C H B
B – T h e la r g e s t p h y s ic a l m e m o ry a m o u n t o f th e s m a lle r s iz e m e m o r y m o d u le
C – T h e r e m a in in g p h y s ic a l m e m o ry a m o u n t o f th e la rg e r s iz e m e m o r y m o d u le
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Intel Core i7-620LE/UE, i7-610E, i5-520E and Intel
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Flex Memory Technology Mode
T O M
N o n i n t e r le a v e d
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a c c e s s
B
D u a l c h a n n e l
in te rl e a v e d a c c e s s
B
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Celeron
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Processor P4500, P4505 Series
Datasheet Addendum
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