I got a Promise Pegasus R6 with 6 x 1TB drives. The Seagate ST4000DM000 4TB disks are now officially in the hardware compatibility list of the Pegasus R6. I am replacing all 6 1TB drives with 6 of the Seagate 4TB drives. I use RAID 5 for all 6 disks. I have Mac OS X 10.8.4. I use the R6 primarily for video editing, photo editing, and storing iTunes media (lots of large HD video). Some questions: 1. When I create the logical disk, should I use the 512 byte sector size default, or should I use the 4KB sector size? 2. In Disk Utility, one can specify the block size for the Pegasus disk. The default is 32KB. Is this block size unrelated to the sector size used to create the R6's logical disk? 3. In Disk Utility, should I use a larger block size (large than 32KB). Can I just change the block size in Disk Utility without affecting the data in the R6's logical disk? 4. For stripe size, the R6 default is 128KB. I plan on using 256KB stripe size. Yes, I know smaller files won't be spread across all the disks, but for my use (large video files, mainly), I was wondering if a larger strip size like 256KB would be better than the default 128KB. 5. Another possible approach, rather than optimizing the aforementioned parameters, is to just stick with the defaults (512 byte sector size, 128KB stripe size, and 32KB Disk Utility block size), and not worry about it, if the performance differences would be negligible, since one school of thought is that maybe the default values are better tested by Promise and might be more reliable. I'd also like to hear from Promise Pegasus R6 & R4 users who purchased their units with 3TB or 4TB drives. Can you look at what stripe size was used by Promise? Thanks.