Mac Pro 1.1 memory upgrade: My newly-acquired Mac Pro 1.1 has 6Gb, 4x1Gb on riser A and 4x512Kb on riser B. I've bought four 2Gb sticks, so plan to double the RAM to 12Gb. Nothing I've read on the web seems to suggest that "what goes where" matters with 1.1 RAM upgrades, apart from which slots should be filled first if they're not all filled. Is this right, please? Is there any performance gain in putting the 2Gb sticks in particular slots? Thanks, Stuart.