I have recently purchased two PowerEdge 840's. Each has the internal SAS 5/IR Controller, with 4 x 250GB SATA drives. The config of the disks is two drives are mirrored to boot the OS, and the other two are not raided as the data can easily be restored. Both these machines are installed with Windows 2003 SP1. All the latest drivers are in use.
I have been VERY disappointed with the disk performance. Copying an amount of data ( 8GB sql database, single file) is taking literally 20 mins to copy. The OS becomes unresponsive. Any ideas ?