Cyberdog said:
Hi,
I have an Asus A7N8X - E Deluxe M/B, I also have 512MB 184 - pin Dimm
DDR400 PC 3200 unbuff memory, which has eight chips on either side. I
recently got another 512MB of the same memory, which according to the
Crucial website is the same and has the same item code on it. The thing
is the new memory only has eight chips on one side.
Could someone please explain how both sticks are the same.Thanks
You should verify you got the right memory, by observing in Windows
whether you are seeing the whole 1GB or not.
Memory chips come in different sizes. The chips on the new DIMM
could have twice the number of memory bits inside each chip.
A 512MB stick can be made with (16) 32Mx8 chips. This is the normal
way of constructing a mainstream DDR memory module.
A 512MB stick can be made with (8) 64Mx8 chips. The 64Mx8 chip
has been around for more than a year (Samsung), and maybe in this
case, Micron is making them too.
(Note: The naming convention "32Mx8" is in bits. Dividing by
8 gives bytes, and in that case would be 32MBytes. Times 16 gives
a total of 512MBytes of memory.)
To construct a bank of memory, enough chips must be put side by
side, until a 64bit wide datapath exists. The example I gave
above, of (16) 32Mx8 chips, is enough to construct two
(8) 32Mx8 banks (sometimes termed ranks). The banks sit in
parallel on the memory bus.
The (8) 64Mx8 config is enough for a single bank of memory.
When a second set of (8) 64Mx8 is added to that module, it
becomes a 1GB DDR stick. You may even see room on the back of
the module to add chips like that, as the same PCB blank is
sometimes used for two different memory stick products.
I hope that isn't too confusing.
Just check in Windows and see if you got your money's worth.
And, lucky for you, the Nforce2 dual channel controller is
tolerant of mismatches like that. Using these two sticks
of memory, if you use slot1+slot3 or slot2+slot3, the
BIOS should report dual channel mode. Dual channel doesn't
mess with the memory capacity, but should give you the
total of 512+512 = 1024MB.
If you ran those two memory sticks on a P4 dual channel
motherboard, it would be forced to run in single channel
mode, due to the differing dimensions of the memory chips.
Nforce2 is fortunately different.
HTH,
Paul
