I have a question I do not understand.
If I get a notebook with 3Gb (1x2048Gb + 1x1024Gb all modules dual channel). Does the 3Gb work with Dual Channel?
Or...It must be 2Gb or 4Gb to be able to use dual channel?
I'm sorry I don't have an answer to your question but I was about to post a thread with the same title, lol.
I bought 2GB (2*1024) DDR2 6400 ram, but 1 module was bad (didn't let my computer even POST), it's corsair DHX 4-4-4-12, and stupid compusa is out of stock of it now so I can't get my replacement, so I thought of just grabbing another 2GB while i I wait, will 2x 1024 work in dual channel if theres another 1x1024 also in there? Is it better to get 2GB and take out the other one or will it perform better with all 3 of em in there?
AFAIK you need two sticks to run dual channel that are of the same size, otherwise you run single channel. I am running 3GB in dual channel and the configuration that i need to do that is 2x1GB and 2x512MB for a total of 4 slots used, the 1GB sticks in channel A and the 512MB sticks in channel B. (on an ASUS A8N-SLI Deluxe)
the debate can be made about more RAM in single channel or less RAM in dual channel, I am not an expert so I can't give expert advice, HOWEVER, my experience and my perception is that it is better, if we are talking GB's of RAM to have 3 v 2GB in single channel than 2GB in dual channel. again, that has been my perception, im sure there are benchmarks that can prove or disprove my perceptions. if we were talking 2.25GB in single channel and 2GB in dual channel, i would go with the 2GB in dual channel.
2GB in dual channel is better then 3 GB in single channel. So either pop a stick out or throw another stick in. Be aware though that if you pop another stick in to make it 4gb of ram then you will need to upgrade to a 64 bit OS becasue a 32 bit system will not recognize all 4 gig's due to capacity issues involving the addition of system memory.
Although buying another stick does enable you to have a little over 3 gigs of ram operate in dual channel mode. Kind of a catch-22 if you don't buy a stick you have a gig of memory laying around doing nothing, if you do then you have another stick of ram that isn't getting it's full values use. Ideally for best memory performance you get 4 gigs of ram upgrade to a 64 bit OS.
I'm not sure that I agree the 2 in dual is better than 3 in single channel mode. However you need to look at the MB documentation. On my last couple of boards mixing would result in matched pair running in dual channel and the odd stick running in single channel.
In real world applications there is very little difference while the synthetics tell a different story. I would always take 3 over 2 personally.
I'm really curious how this works as well. I just bought a notebook and one of the options was a 3GB dual-channel setup. I'm wondering how they would achieve this. One thought is that there is no rule against making a 1.5GB SO-DIMM, but I figured I would have seen it. Another thought is that they are putting in 4GB, and somehow limiting it to only show three, but that doesn't make a lot of sense either, so if anyone knows the answer please enlighten me.