On 12/17/2010 10:52 PM, mm wrote:
On Fri, 17 Dec 2010 19:07:59 -0800, wrote:

mm wrote:
On Wed, 15 Dec 2010 22:17:24 -0500, Ben
wrote:

On 12/15/2010 9:52 PM, mm wrote:
Memory: Does it matter if big DDRs are firsr or second?

Posted to alt.comp.hardware and alt.sys.pc-clone.dell, since the
computer is a Dell and I started the topic in that group, but have
broader questions now.


I have two 512M and two 1G DDR[1]s and they are the same speed PC2700,
the same 333, the same CL 2.5, the same non-ECC and assume everything
else the same except the brand and size.

Does it make a difference if the big pair goes in the first pair of
slots, or if the small pair does???

Is this true for DDR2 and DDR3 also?
Just to be perfectly clear, if you are talking about Dell Precision 360,
Dimension 4600, Optiplex GX270, or Dimension 8300,

It was meant as a general question.

I'm 99% sure I've read that *faster* memory should go in the first
pair of slots, and that makes sense so that one should use the faster
memory most of the time.

How did you determine that?

I didn't determine it. "I'm 99% sure that I read it." It makes
sense, to me, and a reason it makes sense would be so that it used
faster memory more often that way.

The first memory allocated may or may not
be from any particular address space and the area most accessed may or may
not be related to the address space assigned to that function? yes? no?

I don't know. You end your sentence with a question mark, so I guess
you're not saying one way or the other.

My concentration was on whether large DIMMs should be first or not.

If the answer to your question means that it doesn't matter if faster
DIMMs are first, then it likely doesn't matter if large DIMMs are
first.



But here the speed is the same, only the *size* is different, so does
it matter which one is first?

two memory slots have
black DIMM clips and two have white clips. A matched pair has to go in
a pair of DIMM slots with the same color of clips.

Yes, thanks, the computer I'm working on now is a Dell 4600 and the
manual made that clear.

As a rule, I install
the larger capacity memory in the "first" pair of slots.

But is that a personal practice, or maybe a habit left over from fast
vs. slow memory, or is it really based on some benchmark testing or
recommended by engineers or so forth?

Which is the
"first" pair of slots? Usually the one nearest to the CPU and its mate
with the same color of clips. But when in doubt, read the owner's
manual. Same for DDR2 and DDR3.

These boards all have Intel 865 or 875 chipsets, which dictate the
memory configuration rules.

Way back when I worked in mainframe software development, we and tech
support used to write "RTFB" responses, telling customers the answers to
their questions or solutions to their problems and telling them to read
the ^^&&*(_* book, where the answer could be found... Ben Myers

The Dell owners manual didn't go into such detail.

Thanks again.


It doesn't matter if faster DIMMs are first. See my other response. It
MAY matter if large DIMMs are first. Again, a read of the owner's
manual or the chipset spec will tell if it does matter... Ben Myers