I have a g4 digital audio desktop mac with, 384mb Samsung ram (2 sticks one is 256mb the other 128mb) and I also got an additional 256mb ram stick made by PNY that I bought seperately, equaling out to 630mb SD RAM. The samsung dimms where in the machine when I got it. And I noticed that when I copied files to the hard drive or external HD or anything it is super slow. My computer requires pc133 168 pin modules and the guy at best buy told me the PNY would work. I upgraded my processor to a sonnet 1.4 ghz and before & after installing the new PNY Dimm my computer still copies files at 2mb a second which is slower than my 600mhz I mac. I tried removing the new dimm and it goes faster then with it in. I am so confused because my buddys macbook pro copied 7gb off my external HD in ten minutes!!! and he has 512mb ram. Can anyone give me some pointers on what to check for as far as hardware? I am a beginner when it comes to RAM so please all help is appreciated. Oh and I also tried removing all the ram and booting up with each one individually, they all work fine..... So confused.