i took possession of a preconfigured dell precision m90 laptop sometime last year. it came with 2gb of ram. as a result of 'chook eye' i decided to upgrade to 3gb of ram-  since the system can support 4gb of ram(actauly any sys running a intel 945 v chipset will only see 3.25gb of ram - but thats another story)

in typical murphy fashioon, it was after i bought 1 gb of ram at pc village, got home and opened my system that i found that the laptop only has 2 DIMM slots ( i'd assumed that it came with 4 DIMM slots)which means if i want to upgrade to 3gb i need to buy a 2gb ram stick .which brings me to my question-

it appears there something called dual channel mode, which implies that ram must be paired ie 512 to 512, 1gb to 1gb, 2gb to 2gb .

it appears there may be some issues in using 1gb of ram with 2gb of ram(unpaired mode) . i haven't found that much info on the net.

dakmanzero, r u there?

anyway, i'd appreciate if anyone could confirm if my system will not support unpaired ram, or if it will take a performamnce hit if i choose to use it. thanks

I have only experienced that with a Dell Server. i have never experienced it with a laptop. I think your best bet would be to take ur PC to PC Villa so they can test.
In the case od servers, if the RAM modules dont match, it will notify at bios. So i gues it should be the same for Laptops. If it wont work, it wont boot.
Hope this helps

Well, your systems would. . .should still work just fine with the unpaired memory. Memory pairs are necessary when you want to operate the memory modules in dual channel mode. Benchmark tests have shown that there's almost no significant improvement in running dual channel mode over single channel mode.

In your case, the 1GB + 2GB memory modules would result in 3GB in single channel mode. Within the bounds of my knowledge, there's should be no adverse effect in this pair.

You could read some more about these on this site: Memory Architecture

@ maleeq,

thanx. . .

now if i can just convince the dude who sold me the 1gb ram to take it back. . .( sort of like a camel going thru the eye of a needle. . . )

If the dude is reasonable, that should not be much of an issue. . .atleast, since you'll be getting another memory module from him still.