The following are key references for properly tuning the MD3000i for performance.

The support matrix has the details of supported systems that Dell tests and that can be used for reference; this is updated on a regular basis.

Dell™ PowerVault™ MD3000i Support Matrix
http://support.dell.com/support/edocs/systems/md3000i/en/SUPPORTMATRIX/Sup_Matx.pdf

The IP SAN best practices has information on configuring the network and switches while the array tuning is focused on optimising the virtual disks.

IP SAN Best Practices PowerVault MD3000i Storage Array
http://www.dell.com/downloads/global/solutions/public/white_papers/IP-SAN-BestPractice-WP.pdf

In the Array Setup and iSCSI Configuration manual (keyword search: "policy") there is an explanation and example of using load balancing policies to increase the bandwidth with multiple iSCSI sessions; finally, information is provided to help optimise Microsoft Exchange.

PowerVault MD3000 and MD3000i Array tuning best practices
http://www.dell.com/downloads/global/products/pvaul/en/pvault_md3000_whitepaper.pdf

Array Setup and iSCSI Configuration
http://support.dell.com/support/edocs/systems/md3000i/en/2ndGen/IG/HTML/postinst.htm#wp1005566

Best practices for Microsoft Exchange Server 2007 and PowerVault MD family
http://www.dell.com/downloads/global/products/pvaul/en/exchange2007-md3000-i-bestpractice.pdf

MD3000i Quick Links

PowerVault MD3000i Storage Consolidation Study	MPIO to PowerVault MD3000i with Microsoft iSCSI Initiator
Performance Monitoring with MD3000i	Scripting with MD3000/MD3000i
Blogs: Combining MD3000i with Virtualization A Tale of Two Subnets for MD3000i	Data Protection Using Premium Snapshot and Disk Copy Features of the MD3000 and MD3000i
Video Demos: MD3000i Installation and Configuration Part I MD3000i Installation and Configuration Part II MD3000i Snapshot Demo	MD3000i Configuration Utility