NFORCE2 and different size ram.

[larciel]

i currently have Shuttle SN41g2 and two 256mb memory

i'm thinking about upgrading, but two 512mb is overkill for me.. so i'm thinking of getting one 512mb and another 256mb .. they will be same ram (kingston hyper x series)

would that cause any problems because the size of the ram is different? (something i should know w/ TwinBank or wahtever the nVidia named their dual memory system?

tia

 

[Lord Evermore]

It will work, but the dual-channel performance will only be effective up to a certain point. Once you use enough memory to pass the 512MB point (256MB in each module), the chipset will only have memory available over a single channel.

Really not much point to just getting 768MB. Memory isn't that terribly expensive, and you'll always have it available later on when you decide a gig isn't overkill. Of course, 512MB should be plenty anyway.

 

[larciel]

so are you saying w/ nforce2 , anything over 512mb will be used in single channel?

or just when the memory sized isn't matched?

 

[Lord Evermore]

Only when it's not matched. If you have a 256MB and a 512MB, then the controller can use dual-channel for the bandwidth. But if you use up a full 512MB (give or take since it may not fill the memory symmetrically), then one of the modules is filled up while the other still has space. Any more data has to go to the available memory over only one channel. It isn't an exactly even process, since data may be emptied from the smaller module, opening up space so that dual channel can be used for a little bit of data, but overall, as data is being swapped in and out of memory, you'll end up with some of the data having to go over the single channel.

 

[AgaBoogaBoo]

Heres a little simpler explanation:

Say, a game you play loads 512mb of files into the RAM. In this case you have a 256mb stick an a 512mb stick.
For explanation purposes assume that the OS uses no RAM whatsoever, hehe.

Now that the game has loaded, all the space on the 256mb stick will be used up while half of the 512mb stick while be used up. Anything else loaded into the RAM will go the 256mb LEFT on the 512mb stick. Thats where only one channel is being used.

 

[Lord Evermore]

I thought that's what I said.