Can anyone tell me please if I can use these DIMMs?
1GB DDR 2 667 (here is
picture)
Because my mothers board manual says: "Double-sided DIMMs with
x16 organization are not supported"
(here is
link)
Or are these the ones I can't use, because they are double sided and
have 16 chips? May be somebody could explain, because looks like
there are many such boards who don't support this thing. Previously I
had ASUS P5LD2-VM and it said the same.
Download a sample datasheet here. Go to page 226 and read section
10.2.2 "DRAM Technologies and Organization"
http://www.intel.com/design/chipsets/datashts/307502.htm
"all standard 256-Mb, 512-Mb, and 1-Gb technologies and addressing
are supported for x16 and x8 devices"
Standard means, as defined by JEDEC. Notice that really small
memory chips (128-Mb) are not supported. The 256-Mb are
used to make 512MB DIMMs.
"Version A = Single sided x8
Version B = Double sided x8
Version C = Single sided x16"
AFAIK, the "version" word is something that JEDEC might use.
If I use (8) 32Mx8 chips, that forms a single sided or single
bank 256MB DIMM. That would be an example of a Version A DIMM.
If I use (16) 32Mx8 chips, that forms a double sided or
double bank 512MB DIMM. 8 chips on each side. Quite a common
config. That would be an example of a Version B DIMM.
If I use (4) 16Mx16 chips, that forms a single sided or single
bank 128MB DIMM.
The x8 or x16 refers to how many data lines each memory chip has.
If you use (4) x16 or if you use (8) x8 chips, that makes a 64 bit
wide bank. And 64 bits is how wide the data bus is on a DIMM,
and how the chips are to be organized.
Now, there is no Version D. Why ? If you took (8) 16Mx16
chips, put four on one side of the module and four on the other
side, for a double sided x16 DIMM, would it work ? Yes.
But it is just as easy to take (8) 32Mx8 chips and place them
on a single side of the DIMM. Soldering chips to just one side of
a module is half the work of soldering them to both sides of
the module. "Version D" is outlawed, because it makes no
manufacturing sense.
I hope you will not be able to find a DIMM which violates
the rules.
I'd look this info up on the JEDEC site, but you never know
whether the necessary info will be downloadable or not,
and I'm too lazy to check
If you buy a 512MB or a 1GB DIMM, I don't see any reason to
be concerned that you will break the stated rules. I haven't
heard of 128Mx4 technology being used on DDR2, and as a result,
maybe it is a bit safer to buy 1GB DIMMs as DDR2, than it
was to buy 1GB DDR modules.
Since you did not post any links, I cannot say anything about
what you are interested in buying.
Paul
