What should the memory configuration be

memorywindows-server-2003

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.

Best Answer

  1. Keep your existing memory. You may need it during the lifespan of the machine.
  2. On SMP-style machines, especially the ProLiant boxes, there are diagrams of the memory slots on the internal side of the lift-off cover. Usually there is a suggestion there if memory interleaving is needed
  3. While you can get away with non-interleaved style installation, I usually stick with it just for symmetry. It also allows you to set any BIOS settings to enable interleaved memory access.
  4. You did check your BIOS settings before placing it into production, and recorded their settings, didn't you? Otherwise, you'll need to reboot your machine to get into the BIOS to determine if there is interleaved memory support on the mobo.
  5. Try to buy your memory in pairs. Just trust me on this - you'll have less grief when you have paired memory, especially in a server that has separate memory banks that are unified by the mobo's chipset.
  6. The answer in no. 5 is meant to be more of a "better safe than sorry" answer, rather than a "cargo cult" answer. Why chance it, and with memory prices at reasonable levels at this point in time, why bother? Stick with pairs of matched memory, or if you don't want to buy sets of sticks together, get multiples of two for the same type of stick.
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