Thank you for the information. Unfortunately, there are no Intel® Xeon® Processors supporting the Intel® Virtualization Technology for Directed I/O under the LGA775 socket.
For additional details on Intel® Xeon® Processors supporting this technology under a different socket, we would recommend to access:
Well for LGA775 processors I believe VT-d support is more on the chipset instead of the CPU. For example if you're using a Xeon 3200 series processor together with a 3200 MCH + ICH9 chipset, the VT-d could be supported. For more information, refer to http://www.intel.com/content/dam/doc/datasheet/io-controller-hub-9-datasheet.pdf.
I already owned a server with vt-d support, but with Q9300 processor and motherboard with Q45 chipset. The same motherboard with a processor without vt-d support doesn't allow to enable this feature from the bios,
therefore, it is essential that also the processor must be equiped with vt-d support to enable this feature from the bios.
Finally the Xeon 3200 series don't support vt-d also if it installed on motherboard with Q45 Chipset (ICH9DO).
Other sources have told me that only some 775 QuadCore (ex. Q9600, Q9300) have vt-d support. Confirm you?
This is something different from what I knew. Maybe the term "VT-d" is too general here as there are a bunch of features included. Check the white paper: Enabling Intel Virtualization Technology Features and Benefits