Datasheet

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Chapter 1
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Personal Computer System Components
Although it’s not the make-up of the memory that leads to dual-channel support, but
instead the technology on which the motherboard is based, some memory manufacturers
still package and sell pairs of memory modules in an effort to give you peace of mind when
you’re buying memory for a system that implements dual-channel memory architecture.
Keep in mind, the motherboard memory slots have the distinctive color coding, not the
memory modules.
I Can’t Fill All My Memory Slots
As a reminder, most motherboard manufacturers document the quantity and types of mod-
ules that their equipment supports. Consult your documentation, whether in print or online,
when you have questions about supported memory. Most manufacturers require that
slower or single-sided memory be inserted in lower-numbered memory slots than faster
or double-sided memory. This is because such a system adapts to the first module it sees,
looking at the lower-numbered slots first. Counterintuitively, however, it might be required
that you install modules of larger capacity in lower-numbered slots than smaller modules.
Additionally, memory technology continues to advance after each generation of mother-
board chipsets is announced. Don’t be surprised when you attempt to install a single mod-
ule of the highest available capacity in your motherboard, and the system doesn’t recognize
the module, either by itself or with others. That capacity of module might not have been in
existence when the motherboard’s chipset was released. Consult the motherboard’s docu-
mentation!
One common point of confusion, not related to capacity, when installing memory
includes lack of recognition of four modules, when two or three modules work fine, for
example. In such a case, lets say your motherboard’s memory controller supports a total
of four modules. Recall that a double-sided module acts like two separate modules. If you
are using double-sided memory, your motherboard might limit you to two such modules,
comprising four sides (essentially four virtual modules), even though you have four slots
on the board. If instead you start with three single-sided modules, when you attempt to
install a double-sided module in the fourth slot, you are essentially asking the mother-
board to accept five modules, which it cannot.
Types of Memory
Memory comes in many formats. Each one has a particular set of features and characteris-
tics, making it best suited for a particular application. Some decisions about the application
of the memory type are based on suitability; others are based on affordability to consumers
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