12GB Kit

[Tazdaman]

Hi,

I currently have 6GB in my Mac Pro (4-core Xeon 3500 Series) 3rd Gen. Early 2009 and looking to upgrade to 16GB as I use it mostly for video editing. I am not to sure about which make of Ram to buy but I head the name Crucial pop up quite often. I did a scan using the software they provide and it gave me a message saying


Memory Type: DDR3 PC3-8500, DDR3 (ECC)
Maximum Memory: 16GB
Currently Installed Memory: 6GB
Total Memory Slots: 4
Available Memory Slots: -2
Your system may support multiple memory configurations based on the density, quantity and type of memory modules installed. Please consult the documentation for your specific system.


To get to 16GB would I have to replace all my RAM and buy 12GB kit (4GBx3) ?

I had a live Chat with Crucial and they said they did not understand the -2 slots message and it was best to speak to Apple. I have been on hold now for 30 mins trying to get an answer.

 

[wonderspark]

You'd need 4GBx4 or 8GBx2 to get to 16GB.

 

[Tazdaman]

You'd need 4GBx4 or 8GBx2 to get to 16GB.

ok I just checked my Mac I have 8 slots

On the right hand side there are 3 x 1 GB sticks with 1 slot free and at the back on the left hand side i have 3 x 1 GB sticks with 1 slot free.

If I were to fill the bottom right with 4 x 1GB and then buy 4 x 2GB sticks I could get 12 but is this a good idea?

 

[wonderspark]

You threw me off with:

I currently have 6GB in my Mac Pro (4-core Xeon 3500 Series) 3rd Gen. Early 2009

Thought you had a single CPU, not a dual CPU. I assumed you got the extra 3GB of RAM (since singles shipped with 3GB, duals shipped with 6GB) from somewhere else. So, you have two 5500 series CPUs, eight RAM slots.

I'm of the opinion that matching RAM is better than mixing it all up, and you'd be best served by getting matching sets of RAM, such as 4GBx6, and setting the 1GB sticks aside in case of repair work or selling it. Then you'd have 4GBx3 on each side, and 24GB is a nice place to be for video editing. It's cheap from OWC, as seen here for $185.

If the 4GB sticks don't require matching*, I'd put 4GBx1 + 1GBx3 on each side. If that doesn't play well, I'd make it 4GBx2 + 1GBx2 on one side, and 1GBx4 on the other side.

* I say this, because the first set of 4GB sticks I bought were supposedly required to be matched, but now they sell sets that mix with 2GB and 1GB sticks. They look different and have different part numbers, but I've never personally used these newer non-match required type 4GB sticks, and don't know from firsthand knowledge how they play together.

 

[wonderspark]

This illustrates the different kits I mentioned earlier. If you read the special notes on the first kit, it says they don't mix with 1GB or 2GB RAM sticks.

I had this kit:

Now they sell this kit: