"Martineau said:
Thanks Paul,
If I cannot find the module is there another solution with using additional
module (eg PC3700 mem) and still use dual channel? Will the mem have to
match exactly with the PC3500 mem I have now?
Martineau
Answering that question would require knowledge of how the BIOS was written.
For hardware, what is required is the same "topology" for the modules.
If one module uses 32Mx8 bit chips, so should the other one. Each
module would have the same quantity of bits inside it, the same NxM array
dimensions for the bits in the memory, the same 4 banks of memory inside
each chip etc. The timing parameters could differ, and it would be up
to the BIOS to decide how to set the timing parameters. A good BIOS code
would discover the slower of the two modules, and use that SPD info to
set up the memory.
(If you don't have it already, you should read a copy of the Intel
memory guide for its dual channel chipsets.)
ftp://download.intel.com/design/chipsets/applnots/25273001.pdf
I see a couple of ways you can answer this question about mixing a
pc3500 with a pc3700:
1) Rather than guess at it, post your question to the "RAM Guy" in the
Corsair forum. Maybe he knows which modules can be mixed.
"Corsair Forums" - maybe try the Compatibility Questions forum
http://www.houseofhelp.com/forums/forumdisplay.php?forumid=128
2) Go to the Corsairmicro web site. The following page lists product:
http://www.corsairmicro.com/corsair/xms.html#xms
If you click on a link under the part number column, a one page
PDF datasheet will pop up. Your current memory is this one:
http://www.corsairmicro.com/corsair/products/specs/cmx512-3500c2.pdf
This is a 512MB, dual bank module (a bank per side of the DIMM),
which uses (8) 32Mx8 chips per side. Access time is 5ns.
2-3-3-7-T1 at 434MHz.
Now, we try comparing it to a different module (CMS512-3700PT)
http://www.corsairmicro.com/corsair/products/specs/cmx512-3700.pdf
This is a 512MB, dual bank module (a bank per side of the DIMM),
which uses (8) 32Mx8 chips per side. Access time not listed.
3-4-4-8-T1 at 466MHz.
So, it looks like the two examples I picked have the same
topology. They are both dual bank and they both use 32Mx8 chips.
The timings are different, so the BIOS is going to have to pick
the slower of the two. (No, I'm not going to work that out for
you. I'd get it wrong.
Check with the "RAM Guy" anyway - it may save the cost of
shipping the module back, if there are some other gotchas
that the "RAM Guy" knows about. Who knows, he may know where
you can buy another 3500.
HTH,
Paul
