V-Max SATA sequential read perfomance

Hello everybody!

Configuration: Symmetrix VMax 32Gb cache, thin pool 13Tb 2-Way Mir with evenly allocation tracks (no disk was added since VMax installed)

I'm stuck at one problem - sequential reading by backup operation or just copy to another location has low perfomance (about 100Mbit/s)

But if I test device by IOMeter with multithread load - perfomance is good... And I don't get it why it so slow on reading operation. I'm copy data from Clarrion to Symm at the same server and speed was impressive, but now...

OS Windows 2003 SP2 x64, partitions was created with DISKPART align=1024 as EMC say.

Any advise, best practice?