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Intel's T6500 -- No VT for you! Sony: You got Vaio VT? We turn it off.

At the time I'm writing this, you can easily find websites still listing the specifications for Intel's T6500 chip as including Intel VT. The T6500 is prevalent in the consumer Notebook space particularly because it was built to work with an 800mhz front side bus, allowing it to go in cheaper motherboards. You'll find the T6500 in a lot of midrange and budget 64bit notebook computers, from nearly all the major notebook manufacturers. Whether or not you care about VT depends on your interest in 64bit Virtualization software from Parallels to VMWare to Sun Virtualbox to Xen to VirtualPC.

VT is a marketing name for the hardware assisted virtualization workaround, originally named Vanderpool, that adds the Virtual Machine Extensions (VMX) instructions needed by VM's like Xen and Sun VirtualBox to provide 64bit OS virtualization. AMD has a similar set of extensions it added, marketed as AMD-V, although they built in the memory segmentation support that alleviates the problem with 64bit memory virtualization as far back as the D revisions of their AMD64 chips. One such website includes this boilerplate--


T6500 contain Advanced Technologies about Intel Virtualization Technology that increasing manageability, security, and flexibility in IT environments, virtualization technologies like hardware-assisted Intel Virtualization Technology (Intel® VT)


Click to see full size screenshot of original Intel specification.
If you were to have visited Intel's own site prior to July 20th of 2009, you would have found information indicating that the chip had VT support. This is a fairly mind boggling omission when you consider that the chip was manufactured, delivered to customers, and has been sold to customers for well over a month before Intel corrected its own site! On July 21st, Intel updated its website, and VT support is now removed from the specs. An Intel representative agreed that the information on the site was incorrect, once challenged by a consumer with a T6500 based machine, who had used Intel's own tools to enumerate the features on the chip.


I am sorry, I was mistaken. Thanks for bringing this to my attention.

The T6500 does not support VT. I used ark.intel.com as my reference, but as you pointed out, the information turned out to be incorrect. The processor feature information for the T6500 contained within ark.intel.com has been corrected. VT is actually not a feature of the T6500.

The processor identification tool is correctly reporting that VT is not a supported feature of the Intel® Core™2 Duo Processor T6500.

John S.
Intel Customer Support
For people who bought T6500 based computers in June or July, there may be an an unpleasant surprise in store for them, the first time they use a virtualization system like VirtualPC, VirtualBox or VMWare workstation, and attempt to install a 64bit guest operating system, be it Windows 7 beta, or Linux Ubuntu. They simply don't work. To help understand why VT is an essential enabler, VMWare has this note on their site:


Intel EM64T CPUs do not have segmentation support in long mode. If the Intel EM64T CPU is VT-capable, it comes with hardware virtualization support (Intel's Virtualization Technology). This hardware virtualization support allows Workstation and VMware Server to work around the lack of segmentation, making it possible to run 64-bit guest operating systems on Intel EM64T VT-capable CPUs.


Intel EM64T is the original name for Intel's 64bit instruction set, licensed from AMD, and subsequently renamed by Intel to "Intel 64". Intel E64T covers all of Intel's 64bit chips, so in essence VMWare is stating a simple fact about Intel 64 bit chips. Without VT's ability to deal with 64 bit memory segmentation, you can not virtualize a 64bit OS. This is by no means a VMWare issue --- you will find similar notes on the other virtualization systems, almost all of which will let you virtualize a 32 bit OS fine. It's only the 64bit OS's that won't work.

To add to the confusion regarding Intel VT, there are numerous computers with VT chips that lack BIOS support for VT. In these systems, the BIOS disables VT, and does not give you an option to turn it on. For example, apparently Sony has seen fit to lobotomize the Vaio Bios by removing the VT option. Worse yet, Sony apparently has no plans to support VT in their BIOS, according to their Knowledgebase, Sony Vaio's don't support Virtualization nor do they plan to.

While not a perfect analogy, this is not unlike buying a turbo charged automobile, only to find out that the car company has hardwired the turbos so that they never compress air.

I stumbled upon much of this story, in the process of attempting to purchase a Sony SR-490 notebook computer, which among other things was to be a development system for me, where I could run 64 bit OS's. Although there is apparently a nice BIOS hack from Serbian software engineer Igor Levicki it only works on select Vaio models, and risks the very real possibility that you might make a mistake and end up with a $1300 brick. As much as I like the Sony, it's not worth it to me to have to hack the BIOS just so I can do something the Notebook's CPU was designed for.

If you think 64bit Virtualization is something you might want to use, buyer beware, when considering any 64 bit computer purchase. Check that the chip supports AMD-V or Intel VT AND make sure that the manufacturer is supporting it in the BIOS. For one of the many reasons you might want to use virtualization, see my previous article on virtualizing a Centos server under Windows or Vista.
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