All,
We have released a formal tip on this which can be found on our support site.
Visual corruption - ThinkPad R400, R500, T400, T400s, T500, W500, X200, X200s, X200 Tablet, X301
Symptom
Visual corruption is observed on the screen. It tends to start out isolated to a given application window, but then quickly starts appearing on all of the other application windows, and the desktop. The corruption will typically appear as garbled text or scrambled images.
Affected configurations
The following configuration:
Microsoft Windows Vista or Windows 7 (either 32-bit or 64-bit)
Intel Virtualization Technology for Directed-IO (VT-d) is enabled in the BIOS setup utility.
There are two memory DIMMs in the system, and they have a different size (e.g., 2GB and 1GB).
On any of the following systems:
ThinkPad R400(*1), R500(*2)
ThinkPad T400(*1), T400s, T500(*1)
ThinkPad W500(*1)
ThinkPad X200, X200s, X200 Tablet, X301
*1: For models with switchable graphics, the system must be in integrated graphics mode to see the failure.
*2: Models with integrated graphics only.
Workaround
Option 1:
Disable Virtualization Technology for Directed-IO (VT-d). This can be done in the BIOS setup utility. When the system is first booting (during POST), press F1 to enter the setup utility. Then enter the Config menu, and the CPU submenu. Change VT-d to disabled.
Option 2:
Make sure that there is only one memory DIMM in the system.
Option 3:
Make sure that the two memory DIMMs in the system are of equal size. For example, both are 2GB.
About VT-d
Virtualization Technology for Directed-IO (VT-d) is a hardware assist for virtualizing device IO (primary DMA and interrupts). VT-d is not required to support running a virtual machine (to Lenovo's knowledge at this time). Some VMMs do require that hardware assist for virtualization be enabled, but this is a separate setting from VT-d. In the same BIOS setup screen, there is a setting called Virtualization Technology, which is the more commonly used feature.
Here is a link to Intel's site describing Vt-d.
____________________________________________
Regards/Cordialement/Cordiali saluti/Mit freundlichen Grüßen/Saludos/
Mark Hopkins
Project Manager, Social Media
Man lernt nie aus...
