hello KiLLz420,
I just saw your message here, about this subject.
I would like to tell you I found a way to enable and turn on VT-d on x58 motherboards. I don't know if there is Full support on that EVGA board from that time, but at least in linux it shows information like is activated.
Let me know if you still interested.
In my case I activated it for E756 (EVGA X58 Sli Micro) but the majority of boards from this chipset from EVGA uses the same modules. So will not be any different to activate to your motherboard.
*UPDATE1:* Just enabled the IOxAPIC to see the effect on Linux and updated the pictures accordingly
*UPDATE2:* While I was successful to activate the VT-d and IOMMU in my X58 Motherboard from EVGA, I believe that there is a reason why they disabled it in the first place. After much search I found a page claiming about the motivations to disable Interrupt Remapping in some systems and the Intel document, about the X58 Chipset from Internet Archive, listing all the problems with that Chipset design. Accordingly to the documents the revisions impacted by interrupt remapping are (0x12, 0x13, and 0x22). The revision number of X58 Chipset can be found by taking off the Heatsink from chip or found in CPU-Z application as I pointed out in the picture from my board.
https://www.suse.com/support/kb/doc/?id=000018235
PDF with Erratas on Intel X58 Express
https://web.archive.org/web/201207280053...update.pdf