Nothing I've found says it does either without the addition of a sas controller.
I did some digging and checked the pdf for answers. http://en.community.dell.com/cfs-file/__key/telligent-evolution-components-attachments/13-4409-00-00-20-20-25-73/PrecisionT1650_5F00_SellingGuide_5F00_ENG.pdf
Looks like it might support it. At the bottom under "Accessorize It" it shows "SAS hard drive
Store your data in a fast,
more secure SAS hard drive"
So I'm assuming it has a controller. Thanks for your help, though. Appreciate the time.