• As far as I'm aware (and do please correct me if I'm wrong) SQL server doesnt know anything about the disk layout or the file layout and their respective physical fragmentation.

    If it needs pages 1, 27, 3 it will request these in that order. It is the drive controllers that work out the most efficent order to get these pages but still returns them in order that SQL requested them.

    Defragging the indexes is easy compared to the physical defrag of the files on crowded disks.