Unbuffered, single-sided or double-sided DIMMs (double-sided DIMMs with ×16 organization are not supported)

4 gigabytes (GB) maximum of total system memory

64 megabytes (MB) minimum of total system memory

ECC and non-ECC DIMMs supported

Serial Presence Detect

Support for DDR266, DDR333, and DDR400 SDRAM DIMMs
Dual CHANNEL Memory Interface where the board has two memory channels with two DIMM sockets eachpport for up to 4 GB of system memory .      

ther are two 256mb MODULES installed now. if i add two 512mb is dual channel.modules will i get the FULL benefit of all modules. the system is dual channelSorry, but I don't quite understand..... What is your question? You gave me your system specs, but I don't know what you want me to do with them... Please explain...

[glb]Flame[/glb]Hello my friend. Actually your aare not clear about yourr question. STILL one that I did understand is that you wana ask "will i get the full benefit of all modules?"
Sure!!! why not you get full benifit?
You can get full benifit by installing two 512 MB RAM sticks and after that your pC will have 1GB RAM!!!

Take care of you and others and be happy.
Bye...
Dur-E-Wahabmy question is will i get full benifit, meaning if i have  two 256mb sticks and two 512mb sticks i should have  a gig and 1/2 of ram right?