Extra Memory: Which slots should I put the faster extra in?

[Nathan Sokalski]

I recently purchased extra DDR2 memory for my machine. Not only is this
single 1024MB piece of memory more than the 2x256MB that came with my
machine, but it is also faster. However, when I installed the memory, I
placed it in one of the empty memory slots. However, if I am understanding
correctly, this means that my machine will not be using this new faster
memory except for situations in which it needs or can make use of more than
512MB. I knew that I rarely needed more than 512MB (although I have had
opportunities in which I did, because before I added this extra memory I
have seen messages saying I was low on memory and should increase the size
of my paging file, which was set to 512MB), but I would like my machine to
use my new faster memory before the memory that came with my machine (it's
faster, and one piece rather than two, so I am assuming it will help
regardless of how much I need). If I put my new faster memory in the first
slot that was used by the memory that came with my computer (and put that
memory in the slot that my new memory is in now), will my computer use my
new memory first? Also, is there a way to determine which physical piece of
memory is being used (or maybe I should say which order they will be used
in)? Thanks.

 

[Jerry]

First, the faster memory will not run any faster than the slower memory
already installed. So, if the 512 is slower than the 1,024 and they are both
installed then they will both run at the speed of the 512.

Second, if you have in Intel cpu that support hyperthreading then you must
install memory modules in pairs to take advantage of the hyperthreading
function of the cpu (which means it will also be faster).

Third, the paging file is hard drive space allocated to memory and has
nothing to do with the amount of RAM installed. You can just increase the
size of it yourself.

 

[Ken Blake, MVP]

2. When you say the memory will not run any
faster than the slower memory already installed,
is this a result of the machine using both the
512 and the 1024?

No. The speed the memory runs at is set by the motherboard. The
"speed" you are attributing to the memory is actually not its speed,
but it's speed *rating*. It's the speed the memory has been tested to
run at successfully. So you could successfully use that "faster"
memory faster on a motherboard that ran its memory faster.

If it is, would it be faster if I remove the 512
and only installed the 1024 (it is faster
and more memory)?

Only if your motherboard has a setting that enables you to change the
speed it runs the memory at.