Single and double sided DDRs

What is the difference please. I am looking at DDR400

"Sam" wrote in message
...
What is the difference please. I am looking at DDR400

One has chips on one side, the other has chips on both sides :P.

Seriously though, a single-sided module is one bank, whereas a double-sided
one is two banks, and for a given size (ie, in MB), each of the chips on a
single-sided module are twice the density of those on a double-sided module.

All motherboards have a limit to the size per bank, so a single-sided module
of a given size may not work where a double-sided module of the same size
would. Some motherboards "alias" banks, so a double-sided module of a given
size may not work where a single-sided module of the same size would,
depending on what other modules are installed.

As an example of the latter, some motherboards have three slots but only
four banks: slot 1 is physically wired to be banks 0 ("front") and 1
("back"), slot 2 to be banks 2 and 3, and slot 3 to be banks 3 and 2.
Subject to density limits, you can use any single- or double-sided module in
the first slot, but the other two slots can only have (in total) one
double-sided module, or two single-sided modules.

Alex

See Anandtech memory reviews from a month or so ago...
They found that the double-sided sticks were slightly faster....

------
Mark



"Sam" wrote in message
...
What is the difference please. I am looking at DDR400