X11 Forwarding (via SSH) & Graphics Acceleration

[s3a]

Hello, everyone.

I'm aware that I need a processor which supports VT-d in order to be able to have 3D acceleration in my VM.

The problem is my two computers don't support VT-d; more specifically, one of my computers' processor only supports VT-x, while the other supports no virtualization whatsoever.

I intend to buy a processor which supports full virtualization in the not-so-distant future, but I cannot do so at the moment.

My attempt to solve this problem is to use my mother's computer, which supports both VT-x and VT-d, via X11 forwarding, such that I could run VirtualBox on my own computers and have them feel like they're running natively, while it is really my mother's computer's processor that is running the guest OS.

When I run the guest OS from my mom's computer while I stand in front of it (instead of using X11 forwarding), the 3D and 2D acceleration options can be chosen and when both are selected, the virtual machine launches without any problem whatsover, however when I try to do the same remotely, only the 3D acceleration option can be chosen and the 2D option checkbox is grayed out (on both of my computers), but if I select the 3D acceleration option, the virtual machine cannot launch, and VirtualBox suggests that the problem could be with a video card driver on my host OS.

I tried remotely running the guest OS with graphics acceleration via both of my computers. In the first computer, I tried with both the proprietary and free Nvidia graphics drivers, and on my other computer, I used Intel's driver, but I get the same problem on both computers.

All operating systems, both guest and host, are debian stable/jessie installations, but all of them are 64-bit, except the host OS on my mother's computer, which is 32 bit (so, my mother's computer is [successfully] running a 64-bit guest OS within her 32-bit host OS).

Is it also necessary for my computers to support VT-d in order to be able to remotely use VirtualBox with X11 forwarding (because if that is the case, that defeats the purpose for me)?

Any help would be GREATLY appreciated!

[noteirak]

VT-d is only for a very advanced feature, which you don't require. What you require is VT-x. so you're good to go!
The problem resides with your remote graphical connection. I don't know how you can get around that. I will let others with more knowledge on that help you out.