For socket 1366/x58 VT-d support is based on the motherboard. I have a MSI X58M that had working VT-d added with a later bios, tested with both a 2009-era 920 and a much later 6 core 970.
Only with newer cpus that have their own pci-express controllers does the cpu come into play.
Regardless, 5.1 has broken some devices in typical vm-ware undocumented fashion, stick with 5.0u1. Honestly though using a hdhomerun prime over the network would be less hassle IMO.
When I stopped caring about super quiet: E5 1680v2 @ 4.5Ghz, 980ti, i750 SSD - JS9500 & Dell P2715Q for dual 4k@60 because reasons
SAN shares over 56Gb infiniband, microcenter + fleabay = severe risks to my wallet