I am looking to set up a RAID 1 drive in my new mac pro (which my credit card was just charged for so it should ship in the next few days!!) I purchased a Western Digital WD Caviar SE16 7200RPM 300Mb/sec 250Gb hard drive to run as the mirror drive but I was wondering which drive I should run as primary, or if it made a difference. The only difference between the drives that I am aware of is that the WD has a 16mb buffer while the pre-installed has only an 8mb buffer. Is it worth the hassle of transfering the OS and main applications over to the new drive? Or will the gains be fairly insignificant? I am a graduate architecture student and I will be using the Mac Pro for rendering, CAD, Photoshop, etc so I expect to be writing massive files on these drives. (potentially over 1Gb per file). Any input? Also, the HD that I purchased says it is a 300mb/sec while the apple website says that the Mac Pro takes 3Gb/sec drives. Is that just theoretical speed or do I need to find a higher speed hard drive somewhere? Finally, I intend to pull the 160Gb hard drive out of my WD "MyBook" external inclosure and put it in my Mac Pro as my M$ Windows hard drive. Is there any reason why this wouldn't work? The HD looks to be about 3.75 inches wide and it is NOT a PATA drive, it looks like it is SATA. I don't really want to void my warranty breaking the thing open if it wont work but I am really tight for cash so buying ANOTHER hard drive is out of the question. Any info would be appreciated!!!