I've searched the forums, but I wasn't able to find the exact answer to the questions that I have about memory on the MacPro. I just ordered a new MacPro with the default 2x512MB RAM, because I wasn't about to pay Apple for extra RAM as their prices are ridiculous. I then read around various forums for suggestions on RAM to insert into my new MacPro. However, I'm still left with two questions and being new to the Mac, I'd appreciate some help from some seasoned Mac veterans. 1. I came across this memory from Kingston as a viable option for some additional memory. Although, the reviews on Newegg.com for it are all positive, I'm still worried about heat issues. Should I be worried with that memory? If I should be worried, what are some other sticks of memory that I would be completely safe using? 2. People also suggested on other forums that having 2x512 MB and then a few sticks of 1 GB might cause problems, because the memory isn't all of the same size. Will this be a real issue? I'm planning to buy 2 sticks of 1GB to add to my MacPro, so that would leave me with 3GB at 2x1GB and 2x512MB. Would it be better to remove the 2x512MB and leave myself with only 2GB of RAM or keep it at 3GB even though the RAM is of different sizes. Your help would be greatly appreciated as I've not used a Mac in about seven years and am definitely quite a newbie as to its current hardware situation. Thanks very much.