Can I leave original Ram in, and install new RAM

Just got my brand, spankin' new Mac Pro. I'm very excited, and getting things setup as we speak. It came with the standard 2G of RAM, but I ordered an additional 10G of RAM to install myself.

Question: Can I leave the old 2G of RAM in and install my new stuff, or do I need to remove and get rid of my old RAM completely before installing/using the new RAM?

-Joey

That depend on if you have a system with 4 memory slots or 8.

What is the configuration of the new memory sticks?

The system has 8 slots. Right now 2 of those slots are taken up by the (2) 1G sticks. I have (4) 2G sticks ready to install.

If you don't really understand what he is saying, start by turning off the machine and touching something metal. Then remove both of the riser cards from the machine. If you have enough slots to install your 10G's of ram then you are good to go and you can add them with the original memory. But, if you have 5 sticks of 2gb ram sticks but only have 4 slots open then you will need to remove what is necessary.

Hope this helps you out.

PS: There is a specific order that the Ram sizes should be installed in on the different cards. Look it up on google before you install them. It will increase your performance.

In total, I have 8 slots for RAM.

In total, I have 6 sticks of RAM. (2) 1G sticks that came with it, and (4) 2G sticks I ordered from OWC.

What I am finding in my google searches is that the pairs just have to match up - is that consistant to what you are saying about the ordering of the sticks? Do the 1G sticks need to go before the 2G sticks, or does it not matter - as long as they match up by pair?

Thank you guys for the help.

Just leave the 1G sticks where they are. When you install the 4 new memory sticks. Put 2 sticks in each of the memory bays, just like the 1G sticks.

In the end you will have 5G per bay.

I thought I read somewhere that the Largest pairs of sticks should go first on the riser cards.

Confusing...

I called Apple. One rep told me they had to be the same. I called back, one rep told me I could use different sizes, as long as they are paired. I found this doc (attached) on Apple.com. It seems to lay out how you can match them.

And I just realized this diagram is for DDR3. I am working with DDR2, so I'm not even sure if this diagram is applicable.

View attachment Picture 1.pdf