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Intel Fixes VT-d Bug in Sandy Bridge-E CPUs

By - Source: Intel PCN | B 29 comments

Intel will be shipping its i7-3960X Extreme Edition and i7-3930K processor in C2 stepping in January, the company revealed in a product change notification (PCN) this week.

The C2 stepping removes the VT-d bug in C1 CPUs, which affected the CPU's hardware accelerated virtualization support.

While C1 CPUs are only running the software-accelerated only mode, the C2 now properly supports hardware acceleration on a hosted OS, Intel said. According to the document sent out on December 9, samples of the C2 Sandy Bridge-E processors became available last week. Commercial retail and tray units will begin shipping on January 20.

Intel told its customers that it does not anticipate "change to customer platforms designed to Intel guidelines." However, if a customer chooses to enable Intel VT-d, "regression testing is recommended to ensure their board is properly enabled," the PCN states. Those customers who prefer their own BIOS will have to install the latest Microcode update to support the C2 stepping.

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Top Comments
  • 16 Hide
    molo9000 , December 14, 2011 12:20 AM
    SteelCity1981For the typical pc user they don't even know what VT-d does let alone use it.


    The typical PC user doesn't buy a $1000 CPU.
Other Comments
  • -7 Hide
    applefairyboy , December 13, 2011 10:04 PM
    God bless us, everyone! - Tiny Tim
  • -8 Hide
    mouse24 , December 13, 2011 10:20 PM
    I am confused, what exactly is VT-d and whats wrong with there being no hardware acceleration? isnt the gpu normally handling that?
  • Display all 29 comments.
  • -3 Hide
    mouse24 , December 13, 2011 10:21 PM
    mouse24I am confused, what exactly is VT-d and whats wrong with there being no hardware acceleration? isnt the gpu normally handling that?


    edit: unless they mean it adds virtualization hardware accel support for virtual cores while running multi threaded apps...
  • 4 Hide
    bejabbers , December 13, 2011 10:38 PM
    Is this something that Intel will replace my c1 with? Or are they saying that everyone with the c1 is out off luck.
  • 5 Hide
    dgingeri , December 13, 2011 10:46 PM
    mouse24I am confused, what exactly is VT-d and whats wrong with there being no hardware acceleration? isnt the gpu normally handling that?


    VT-d is hardware acceleration within the CPU for virtual machines. it has nothing to do with graphics. This is mostly used for (in home and/or regular user situations) virtual machines to run old software that won't run under the current OS, like running Windows XP software in a Windows XP virtual machine while the main OS is Windows 7, or running a Linux virtual machine on a Windows main OS. Most people won't be using it. If they do, VT-d won't make much of a difference for most people.

    I do, however. I use it to make multiple virtual machines to learn stuff for IT certifications. Right now, I'm working on my MCITP-VA cert, running multiple virtual machines from my home server (running Windows 2008 R2) so I can get a better job. VT-d missing would mean great trouble for me, if I were to use it as a server. Thankfully, if I were to get one, I wouldn't be using it as a server since I already have that.
  • -2 Hide
    gtx_560tiuser , December 13, 2011 10:50 PM
    well at least they fixed it :p 
  • -1 Hide
    SteelCity1981 , December 13, 2011 11:17 PM
    For the typical pc user they don't even know what VT-d does let alone use it.
  • 16 Hide
    molo9000 , December 14, 2011 12:20 AM
    SteelCity1981For the typical pc user they don't even know what VT-d does let alone use it.


    The typical PC user doesn't buy a $1000 CPU.
  • 9 Hide
    Pinhedd , December 14, 2011 1:13 AM
    dgingeriVT-d is hardware acceleration within the CPU for virtual machines. it has nothing to do with graphics. This is mostly used for (in home and/or regular user situations) virtual machines to run old software that won't run under the current OS, like running Windows XP software in a Windows XP virtual machine while the main OS is Windows 7, or running a Linux virtual machine on a Windows main OS. Most people won't be using it. If they do, VT-d won't make much of a difference for most people.I do, however. I use it to make multiple virtual machines to learn stuff for IT certifications. Right now, I'm working on my MCITP-VA cert, running multiple virtual machines from my home server (running Windows 2008 R2) so I can get a better job. VT-d missing would mean great trouble for me, if I were to use it as a server. Thankfully, if I were to get one, I wouldn't be using it as a server since I already have that.


    That is not entirely correct.

    VT-x is the set of extensions required to properly secure a virtual machine running in long addressing mode and reduce VM reliance on operation emulation. It is the bare minimum required to run an OS safely in 64 bit mode on Intel CPUs (AMD CPUs can run 64 bit guest OSes purely in software but will still see performance benefits from AMD-V).

    VT-d and AMD-Vi are the sets of extensions required to properly allow a guest OS access to peripherals without having to go through a software layer. This allows guests to access Ethernet controllers, USB controllers, PCI-E controllers, SATA controllers, etc... VT-d is to the chipset as VT-x is to the CPU.
  • -3 Hide
    digitalrazoe , December 14, 2011 1:32 AM
    ~And so it begins ... BugZilla
  • -6 Hide
    A Bad Day , December 14, 2011 2:04 AM
    molo9000The typical PC user doesn't buy a $1000 CPU.

    Never underestimate the stupidity and ignorance of humans.

    Such as an idiot buying an i7 2600k and pairing it with a motherboard that lacks overclocking support, thinking the integrated graphics is sufficient to run Crysis 2 at Directx 11, high resolutions and details.
  • -3 Hide
    notsleep , December 14, 2011 2:25 AM
    ...or a guy spending $4,000 on a laptop for his wife to surf the net with...early adopters are usually not that bright...
  • 6 Hide
    Trialsking , December 14, 2011 2:33 AM
    notsleep...or a guy spending $4,000 on a laptop for his wife to surf the net with...early adopters are usually not that bright...

    but it loads the pages SOOOOOO much faster
  • 1 Hide
    de5_Roy , December 14, 2011 6:03 AM
    :)  intel is doing a good job keeping their buggy cpu away from strict media scrutiny and rolling out the new revision so early.
    if amd had it.......it could become a much bigger deal...
  • 0 Hide
    JimmiG , December 14, 2011 7:51 AM
    Wow, that's a pretty serious flaw for the affected users that need it. Surprised we haven't heard much about this before. VT-d or AMD-Vi are absolutely essential for me.
  • 0 Hide
    CyberAngel , December 14, 2011 8:33 AM
    Looks like even Windows 8 does not use it
    or rather I could not quickly find in on the docs currently available for W8
    Maybe it comes along later or I was sloppy
    Those of you who have a greater tendency to load every doc available (of W8)
    may correct this (possible misinfo), please
  • 0 Hide
    digiex , December 14, 2011 9:13 AM
    This is the perennial problem to early adapters, bugs...
  • 0 Hide
    Pinhedd , December 14, 2011 9:29 AM
    Quote:
    Looks like even Windows 8 does not use it
    or rather I could not quickly find in on the docs currently available for W8
    Maybe it comes along later or I was sloppy
    Those of you who have a greater tendency to load every doc available (of W8)
    may correct this (possible misinfo), please


    Windows 8 is not a virtualization platform. Most hypervisor based virtualization platforms are focused on resource allocation and consolidation efficiency, and so the server oriented Hyper-V probably wouldn't get any real advantage from VT-d and so I doubt that they would implement it yet.
  • 0 Hide
    Anonymous , December 14, 2011 10:11 AM
    In other news, the same CPU is still an 8-core with 2 perfectly good cores intentionally disabled, not die harvested like another company would do, as every Intel chip on every wafer is flawless, bug free, and capable of 5ghz on air.

    Furthermore, most people who would buy this CPU just want a smoother Facebook experience, not to use as a professional workstation to run those virtual machine thingies, whatever they are. They wouldn't be disappointed at all to pay $1000 for a CPU that has vastly inferior VM performance to a $200 Bulldozer CPU due to lack of proper IO acceleration.
  • 0 Hide
    lradunovic77 , December 14, 2011 1:30 PM
    I received latest ASRock update for C2 and i enabled VT-d on my C1 processor and everything works fine. With proper BIOS update it should be good on C1 CPUs as well.
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