virtualbox.org

Is there any way of increasing the display memory above 128MB?

I ask as directx3D does not work. Its failing with lack of memory error.

Anyone help?

Did you read the manual (section 4.4)?
Have you enabled the guests 3D acceleration?
Did you install the Guest Additions in safe mode?

Read manual and set correctly. Display sections shows 128MB and 2D Video, 3D
The error is showing up when running the dxdiag 3D tests.

FAQ question. Try a search.

MajorThorburn wrote:Read manual and set correctly. Display sections shows 128MB and 2D Video, 3D
The error is showing up when running the dxdiag 3D tests.

I suggest you read the manual again. 3D uses the GPU in the host, so the video memory in the guest is irrelevant.

Technically, VirtualBox implements this by installing an additional hardware 3D driver inside your guest when the Guest Additions are installed. This driver acts as a hardware 3D driver and reports to the guest operating system that the (virtual) hardware is capable of 3D hardware acceleration. When an application in the guest then requests hardware acceleration through the OpenGL or Direct3D programming interfaces, these are sent to the host through a special communication tunnel implemented by VirtualBox, and then the host performs the requested 3D operation via the host's programming interfaces.

My host has a NVIDIA GeForce 7950 GT with 256MB and runs Directx Diags with no problems so it looks to me like the VMs display driver is not passing this hardware detail through to the virtual system or there is in fact a limit of 128MB as specifed in the setting setup.

Is it a question?

Yes, its not the real hardware in a vm. Like described in the manual and the faq.

Yes there is a limitation to the amount of vRam that VirtualBox presents to the guest.
No that is not the problem.
You need to install the guest additions (in the guest) while in safe mode and select to install the 3D drivers there.