07-14-2014 07:48 PM - edited 07-15-2014 08:00 AM
[Edit: SOLVED! I didn't realize that VT-d builds on top of VT-x; Hyper-V was able to boot 64-bit VM's just fine. I will post a solution if I figure out why VirtualBox could not boot 64-bit guests.]
Can anyone tell me if Intel VT-x is supported on the Thinkpad T440? I know that it supports Intel VT-d, but the VT-x option is not an option I can enable in the BIOS (version 2.27). Intel ARK shows that the Core i7 4600U supports VT-x, though: Intel ARK - i7 4600U
I'm a power user, so it's extremely frustrating I can't run 64-bit guest VM's.
07-15-2014 07:54 AM
Ah, thank you for the link! I didn't realize that VT-d builds on top of VT-x.
Also, in my frustration last night I didn't try making a 64-bit VM with Hyper-V instead of just Virtualbox. Sure enough, the VM booted in 64-bit mode with Hyper-V. The problem must be that I can't have multiple Hypervisors running at the same time on the machine (Hyper-V must gain exclusive access to the subsystems that allow 64-bit operations).
I'll continue to play around with my configuration (the most likely case will be disabling Hyper-V) and see if I can get VirtualBox to start 64-bit VM's.
07-15-2014 09:17 AM
Sure enough, it was Hyper-V preventing any other application from even seeing the Intel Virtualization enhancements:
Before diabling Hyper-V:
After disabling Hyper-V (using bcdedit /set hypervisorlaunchtype off):
Virtualbox is now happily running a Server 2008 R2 instance. Thanks for the help! Hopefully this helps someone else that runs into the same thing.