Step by Step Guide on How to Enable VT-d and Perform Direct Device Assignment

This guide shows step by step instructions on how to "direct assign" Intel 85276 NIC to a virtual machine using Intel's VT-d technology. For this guide I am using the following hardware and software:


    • Supermicro X8DTN+ Server with Intel Core i7 X5570 processors, American Megatrends BIOS R1.1


    • VMware's ESX Server 4.0 as the hypervisor


    • Microsoft Windows Server 2008 Enterprise 64-bit as the guest operating system

Your BIOS, VMM and guest OS might be different from what I used, however you can apply the same methodology to your hardware and software.

1. First step is to enable VT-d in BIOS. You will not find it under CPU configurations. Go to your BIOS and select "North Bridge" under chipset.


2. Select Tylersburg IOH Configuration.


3. Select Intel VT for Directed I/O Configuration.


4. Enable VT-d.


5. Save and exit. Unplug the power from your system, wait for one minute and plug it back again.

6. Power up your system, connect VIClient to ESX server.

7. On VIClient, goto "Configuration" tab, click "Advanced Settings" under hardware and then click "Configure Passthrough."


8. A pop-up dialog box will appear. We want to confiigure vmnic1 for direct assignment. Select vmnic1 and click OK.


9. Now you will see "Intel Corporation 85276 Gigabit Network Connection [vmnic1]" in the list of devices available for direct access for virtual machines. Reboot your ESX server.


10. Now edit the settings of your virtual machine to which you want to add the pass through device. In our case 85276 network adapter. Click on "Add hardware" and then select "PCI device" as shown in figure below. Click "Next."


11. Select "Intel Corporation 85276 Gigabit Network Connection" from the drop down list and click "Next" button.


12. You will see "New PCI Device" will be added. Click OK and close the dialog box.


13. Power on your virtual machine. Now guest OS will detect a new hardware device that has been added. You need to install appropriate drivers for your device.


14. For Intel 85276 NIC, download the driver file "PROVISTAX64_v13_5.exe" from Intel's website. Double click on the executable and install the driver.


15. You will see a message that "Device driver software installed successfully." You are ready to use your directly assigned Intel Corporation 85276 Gigabit Network Adapter.



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zloidooraque's picture

hi! i hope u read this

plz answer me what does intel means under "i/o devices" exactly?

now i'm buying myself a laptop and i have very good deal for one with 2630 processor
but one of important thing is that i will be using virtual machine with installed iOS(one at a time) much. i need it to be ran nice and smooth
2630 havn't vt-d, 2720 has.
so i wonder, whether 2720 will have greater performance (not counting its higher frequences) while running virtual machine wirh iOS.

so i need to know, what exectly intel means when saying i/o devices.. i understand all those things about hardware ram mapping, DMA and so on, but i just cant get, if this will be critical in my own case. and wich cases it will be critical at, just curious

anonymous's picture

Do you know if it's possible to share a passthrough nic between multiple VMs?


anonymous's picture


Thanks for the detailed notes. So I assume that Northbridge chipset is a prerequisite for this feature? I have an HP ML110G4 with a Xeon 3050 CPU and the Intel 3000 chipset. No good?



anonymous's picture

I am writing a piece of code to detect whether vt-d is available in the chipset. So far I haven't found any way of doing this directly. Can someone please let me know if there is a way to this (preferably on Linux).

Aamir Yunus (Intel)'s picture

You might be interested in my other post about, "Installing VMware tools on a VM created using ESXi:"

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