Memory Purchase

Idk if you tried searching but this has been discused. It seems as long as all 8 slots are filled you will get the "best" performance. Of course you need to use 4 pairs of matching. BUT supposedly all the pairs dont have to match each other.

In other words, you should be fine buying 6x1GB and adding that to your machine.

 

Last month i purchased 4 GB (2 X 2GB) RAM for my brand new Mac Pro, to add to the 4GB of Apple's RAM. I just pulled out OWC's RAM because of operating temperatures of 260 degrees! My new ATI 1900 graphics card (which is located just above the OWC RAM) overheated and went buggy & had to be replaced. The RAM temps remained high (for the top card only) until I pulled out the OWC RAM. Now, the temps run about 140 degs. I'll call OWC for a solution in the morning. I suggest you get the free iStat temperature widget.

 

Did you try putting the "hot" ram in the bottom slot? Temp seems to be higher in riser A than B.