We have a server (ProLiant DL585 G1 by HP), which hosts Windows 2003 x64 R2 with SQL Server 2005 x64 and a host of other apps.

It currently has 6GB of RAM. We are currently very memory constrained and it's clear that we need to get more memory. 8GB will probably do the trick, however, we are not sure as to what memory configuration will give us the biggest performance buck.

Currently all 8 memory slots are filled (4 slots have 1GB chip, while the other 4 slots have 512MB chips). Should we throw the 512MB sticks away and just replace them all with 1GB sticks?

If we decided to go with a higher memory configuration (e.g. 10GB or 12GB or 16GB), is it advisable to keep all the sticks of the same size or it does not matter?

I was once told that interleaved memory requires (for better performance) that memory should be in multiples (e.g. 2 or 4 or 8 or 16, etc...). I am not even sure that the server has an interleaved configuration (and don't know how to find out), but is this true?

Thanks.