The disk doesn't decide where the data will be lpaced, but the Storage Processor does. And it creates a LUN as far "left" as possible (in non fragmented space).
How would you short stroke data on disk with the CX4 series.  If I had a RG with 700GB of  availble space and I create a Lun using 250GB and never used the rest of the Disk space would this be classed as Short stroking?  if indeed that is the case how do you know you are using the outer edge of the Disks ( they spin faster) or is it the case the first Lun you create on a RG will always use the outer edge of the disks first and subsequent Luns will be bound moving closer to the inside tracks?  or is there no way with clariion you can control data on disk placement?
Disk short storking