i have gigabyte GA-945GCMXS2 motherboard, i have 512 mb(x1) of ram(DDR2-667) installed in one slot, and other slot is empty. I want to perform a memory upgrade(preferably 2gb in other slot), but the problem is the manual which came with it says it supports max 2gb, while the sitehttp://www.gigabyte.com.tw/Products/Motherboard/Products_Spec.aspx?ClassValue=Motherboard&ProductID=2521&ProductName=GA-945GCMX-S2 says the mother board supports 4gb. The initial guess i make is that in each slot i can put max/2 amount of memory. i.e 2gb per slot if its 4gb.
So what could be the solution? what memory i should put? If i try putting 2gb in a slot for experiemental purpose, would i be frying the ram?
P.S.: board supports dual channel

P.S.: board supports dual channel

but for dual channel to work both chips have to be same ,a matching pair .so adding a 2 gig with the 512 ,it will only function in single Chanel mode ,it looks like the board takes 2x2 to = 4gig ,this would work in dual Chanel.
and no it will not burn out the ram if you try a 2 gig stick in the slot .if not supported it will just either not boot or boot but not register the ram as working

a couple of quotes from your link.

Why I wrote: To correct some misconceptions that are out there about what is dual channel. And to try and help with some of the questions. “Will this be Dual Channel”. This only applies to Notebooks not Desktops, they are very different, as Notebooks have two slots A & B channels and Desktops have four slots 2A & 2B channels.

you are using a desktop!!

Do I have it? Most current Notebook Motherboards support it, remember it is the Motherboard that determines if you can use it, not the RAM. RAM is sold in “Dual Channel kits” as both a convenience and marketing ploy.
And what it actually means is that you just get two identical RAM sticks, which is guaranteed to work because dual-channel relies on both channels having similar memory configurations.

Or to put it another way, we have one 64-bit connection going out to the 1GB stick, and another 64-bit connection going out to the 2GB stick.
So depending on what part of memory is being read, we'll get an effective connection of either 64 or 128 bit. If they were symmetric, the data would be distributed evenly, so you'd always get to use the 128-bit interface, but now, more data can be stored in one side than the other. So obviously, we'll sometimes have to refer to that side only. And every time we do, we drop down to single-channel speeds.

that was from post #4
close to what i said /meant

thanx for your valuable guidance.
but, the question that max ram=2gb or 4gb still remains unresolved.
Kindly reply if you have a solution.

thanx for your valuable guidance.
but, the question that max ram=2gb or 4gb still remains unresolved.
Kindly reply if you have a solution.

giga-byte web site says 4 gig total ,so only way to know fur sure is buy or borrow 2 x2=4 gig and try them.
unless you are reading the model # of your board wrong

from gigabyte site in your other post !
1. 2 DDR II DIMM memory slots (supports up to 4GB memory)
2. Supports 1.8V DDR II DIMM
3. Supports dual channel DDR II 667/533 DIMM

* Due to standard PC architecture, a certain amount of memory is reserved for system usage and therefore the actual memory size is less than the stated amount.

Finally i got my answer.
I contacted gigabyte telling them my problem. The answer came was
"This MB can support up to 4GB. The manual was revised "
i used sisoft sandra, it said(max ram=2gb) so also the manual which i got with my board. I still wonder how they(sandra) determined it.
Finally i can safely put more ram in my pc.
Will reply again when my exams get over and i check this out practically.

Finally i installed 2gb RAM successfully. Now my PC has 2gb @800 MHz and 512mb @667MHz, both running in dual channel asymmetric(thats what they call it on POST) mode.
Above all, PC working fine.(showing 2.5gb total RAM)
Thanks Daniweb for your support!!

commented: Same problem. Thanks for the answer. I have 3 gb now. +0