GBHT77 said:
I'm about to build up my first pc with an Asus A7V8X-X, but I'm confused
over how many sticks of DDR memory I can use on this board.
The Asus manual says PC3200 up to 2 banks and PC2700 up to 4 banks.
Crucial says a stick of DDR memory can have 1 or 2 banks? How can I
tell which one it is? Can I fill up all 3 slots on the board with PC2700
or can I only use 2? With PC2100, can I use all 3 slots? What about PC3200?
A 512MB DIMM will typically consist of two 8 chip (x8 bits each) banks.
The DIMM is double sided. It is not currently economical to make a
single sided DDR DIMM at the 512MB size (parts exist but aren't shipping
in volume).
Using a double sided 512MB part like that, you could use precisely
one DIMM at PC3200. Two DIMMs at PC2700.
A 256MB DIMM could be single or double sided. (I.e. one or two banks).
You would have to contact the vendor or manufacturer to see how it is
constructed. Kingston, for example, has a single page datasheet for
their valuerams, that will tell you all about the module. Crucial
modules are made by Micron - Micron has datasheets, but I am not
aware of a way to map the Crucial number to the Micron number for the
DIMM.
Anyway, to max the memory, you would be using 512MB sticks, because
the proper type of 1GB sticks are still too expensive and hard to
find (most 1GB DIMMs for sale are the wrong type). Since the 512MB
will be double sided, that limits you to a 512MB system at DDR400
and a 1GB system at DDR333. If the manual doesn't state any other
limits, then I guess that means you can run three sticks at DDR266
rates, for a total of 1.5GB of ram.
Note that the speed issue is the current operating speed of the ram,
not the rating of the ram itself. For example, you can buy three PC3200
ram, and run them at DDR266 (memory clock = 133, times 2 for DDR). It
is just a terrible waste to buy high spec RAM and underutilize the
clocking.
There is nothing preventing you from experimenting. If you are rich,
you could buy two 512MB double sided DIMMs and try them, adjusting
the memory clock for as much as the memory bus can handle. That would
give a compromise between maxing the memory and running the processor
at a decent rate.
Good luck,
Paul
