Dell Optiplex 790 support VT-d

Zack Hehmann

Feb 6, 2016
I have Dell Optiplex 790. I bought it for $40. It has an i3-2120, 250 GB HDD, and 2 X 2 Gb of DDR3. I'm planning on using it for an ESXi box for Zoneminder and pfSense. I'm wanting to utilize VT-d so I could pass a network card to pfSense. I am looking at buying an i5-2390T for lower wattage, better performance, vPro, AES-NI, and VT-d.

Before I purchase an i5, I was hoping to ask someone with an Optiplex 790 and an i5 if they could confirm that VT-d does indeed work by testing it with ESXi. In the BIOS settings on my Optiplex there is a option for VT-d. The google searches I have done state that the chipset for the mobo is a Intel Q65 -->(look at page 11). According to Intel's ark page the Q65 chipset doesn't support VT-d or vPro. I'm getting conflicting information and it's definitely frustrating.

The mobo is Dell part number 0J3C2F in the one I have.

@fractal or @Boddy Could you please provide what hardware you have in your 790s and let me know if you can get VT-d to work? I'm hoping you have a non K version of an i5 or an i7 you can test with.

Thanks for your time!!

Here is the output from the terminal on the ESXi box:

[root@790-ESXi:~] lspci
0000:00:00.0 Bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller
0000:00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1
0000:00:16.3 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family KT Controller
0000:00:19.0 Network controller: Intel Corporation 82579LM Gigabit Network Connection [vmnic0]
0000:00:1e.0 Bridge: Intel Corporation 82801 PCI Bridge
0000:00:1f.0 Bridge: Intel Corporation Q65 Express Chipset Family LPC Controller
0000:00:1f.3 Serial bus controller: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller
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Active Member
Dec 5, 2016
Chipset support was important in the Conroe and Wolfdale generations since the IOMMU was present there. Nehalem moved the IOMMU to the Processor. You will find lots of info about later Chipsets supporting (Or not) VT-d, but after TONS of googling, I came to the conclusion that "VT-d support" on later Chipsets is Intel way of calling the PCI FLR (Function Level Reset) capabilities of some of the built in Chipset PCI Devices. That is why on later generations you can get Passthrough working on Chipsets that supposedly don't support VT-d. Sandy Bridge is a bit too early for my taste, but is possible that it works that way, too.
A problem that was quite common in Sandy Bridge era platforms is that the DMAR ACPI Tables that the Firmware had were incomplete or broken and thus you couldn't get the IOMMU to a working state without complex workarounds, which is the main reason why I would avoid old platforms. However, that applied to consumer Motherboards, I suppose that OEMs aiming for more serious systems would have got it working. After all, that was the main reason why I purchased my Supermicro X10SAT (Haswell era) when I got into PCI Passthrough with Xen, and now its running with QEMU-KVM-VFIO.