I just purchased a mac pro 3 Ghz quad core machine. It has 1 gig of factory installed RAM. I purchased 8 gigs ( 4 x 2 gigs) of RAM from a vendor to save $$$. The install instructions state that dimms must be installed in equal pairs of equal size from the same vendor. Does this mean that I need to take out the one gig thats in there and install the 4 X 2 gig dimms? What will the ramifications of leaving the original ram installed and adding the 8 gig? Will this damage the machine and void it's warranty? Will this compromise the machines performance because its not a matched pair? Thanks in advance.