6 Replies Latest reply on Aug 13, 2012 11:40 AM by Alexander

    Intel VT-d and VT-x

      I have been working on a feature called pci passthrough ( to implement single root I/O virtualization ) which requires support for VT-d. I want to know if VT-d is a

      1) Chipset feature (or)

      2) CPU feature (or)

      3) PCI device feature


      Please guide me as to what hardware fits my requirements.

        • 2. Re: Intel VT-d and VT-x

          To use Intel Vt-d you need processor that support VT-d _AND_ chipset that support VT-d _AND_ motherboard BIOS that support Vt-d. If you wish to use VT-d you should find motherboard that have VT-d option in BIOS and have correct DMAR table. Some motherboards such as Asus and Gigabyte build on chipsets that supports VT-d but their BIOS don’t have VT-d support. You can find more detailed information at http://wiki.xen.org/wiki/VTd_HowTo

          You can find the processors that support VT-d here http://ark.intel.com/search/advanced?VTD=true

          • 3. Re: Intel VT-d and VT-x


            Would you happen to know any video-cards that are sr-iov compatible? And if so, can I use these sets of hardware to enable Intel SR-IOV and Intel VT-d in tandum? Thanks for your help.



            P.S.I work at JF3

            • 4. Re: Intel VT-d and VT-x


              The short answer is that there are no video cards in the market that support SR-IOV. The long answer is below.

              Intel VT-d allows dedicating PCIe device to VM. When you are dedicating device to the VM it is impossible to use that device by other VM’s.

              SR-IOV technology allows sharing device between VM’s.

              Benefits of SR-IOV Virtual Functions:

              • Bare metal like performance.
              • No CPU overhead and latency issues that are seen in Virtual I/O.
              • Throughput that is only limited by the number of VFs from the same device and actively performing I/O.

              May be we will never see SR-IOV for video cards.

              1. This is nightmare for developers because video card has its own BIOS and own video memory.
              2. Video card BIOS should handle all requests from different VM’s and video memory should be divided between VM’s. That is why the video card performance will decrease dramatically. It will be a slideshow in VM.
              • 5. Re: Intel VT-d and VT-x


                I still have faith that one day it will be available in the market as more groups go virtual, it just makes sense to make graphics rendering virtual and by-passing the virtual manager, incredible. Anyways, if i have a video card for each VM located in my server, would this bring near-true performance? What software is also required to enable VT-D technology? I'm thinking of using windows server 2008 r2 and wondering if i need to use a certain hypervisor or VM managing software. All thin and zero clients seem to come with the managers bundled with them, ncomputing, wyse, etc. I think using Windows multi-point server would be ideal, but it seems that Microsoft isn't selling this to the public...ie"OEMs and their resellers offer options for both Academic and Commercial customers."

                Also, is there a vt-d compatible program that will update thin client codecs or is it hard/impossible to update the codecs? I think the easiest way to do this would be to have zero clients and do all the processing host side, but i'd like to have SOCs and some RAM to do some of the work client side for performance's sake, not to mention lightening network load, but i wonder if NUMO2 and the various other products are in-compatible with vt-d technology. I'm thinking of using the L300, Plugable DC-125, or the E01 Multipoint workstation 1x US by Wyse. Choosing the right combination seems like a chore, but if I do it right, i think it will be worth it. Thanks for your help.



                Update: Is there anything stopping me from using VMware Vsphere Hypervisor, VMware server, and VMware Player all in tandum and not have to liscense any Windows server program to do the same job?

                • 6. Re: Intel VT-d and VT-x

                  The initial topic was about VT-d and VT-x, please start new topic give me the link and I will answer to all your questions.