Hi All, I'm setting up a new equipment for 2005 sql database server, on windows 2008 server, with multiple Raid1 containers: 1 local and external 7 x Raid1. We are at the step of formatting the virtual disks (individual Raids), and there is an option to change the NTFS Block size, ranging from 16K to 8192K, they call it in windows 2008 "Allocation Unit Size". I already did the alignment using dispart to 64. So what is the best option for the block size to select for optimum sql server performance? more background on the database: size of the database is about 15GB data, and about 10GB indexes. reads are about 30% of transactions and writes are about 70% of the transactions. thanks.