gday.i have an asus an8 (gto i thinks) MB, it has 4 slots for ram and can run dual channel. dual channel activates in slots 1/2 and 3/4.i have 4 x 512mb matched ram in atm.
i have a spare 1GB stick, so would there be any advantage by replacing one of the 512 sticks with the 1gb forfeiting the 2nd dual channel offered?

I would sell 2 of the the 512MB sticks on Ebay and with the proceeds buy an additional 1GB stick to match your spare 1GB stick. The cost difference would be small (maybe $30?) and you get 3GB in dual channel.

thanks mate.that is a probable solution, better than either outcome in my case, just still curious as to which option is the best.

It depends on what software you are using, and what you do with your PC.

If you are using apps that use a lot of RAM (e.g. Photoshop with multiple large images) then you need as much RAM as you can get, regardless of if it is marginally slower. Because any RAM will be 10x faster that swapping to disk when you run out of RAM.

If you aren't fully using the 2GB you have today. Then the extra speed is better. And you shouldn't give up the dual channels.

ok, well i mainly use it for gaming and music recording/editing software