AGP Texture Acceleration?

[Tha General]

Alright here is the issue. I am running windowsXP home edition, using the 2400 HD pro pci card, and i have notice when going into DXDIAG, when i run the D3D7 test, the spinning cube is slow and jerking around, rotating weird. But D3D8 and D3D9 is running smooth, their cubes are spinning normal.

So i notice when turning off AGP Texture Acceleration, D3DX7 test the cube is spinning normal like its suppose to be. Now i had this problem with my 6200 PCI card, only difference, i didn't have to turn off AGP Texture Acceleration, the problem was fixed using a different driver.

I have tired every driver for the PCI 2400 Card, and the only way to fix the spinning cube is to turn off AGP Texture Acceleration.

My question, what is AGP Texture Acceleration and what does it have to do with GPU's?

Note: Using a intel motherboard, with 4 pci slots, no agp.

 

[EXCellR8]

I'm thinking that maybe AGP texture acceleration just works better on D3D8/9 better than on with 7. But, then again, I've never tried enabling it while using a regular PCI adapter. All the feature does is force the video card to render 2D textures faster when enabled so disabling it obviously gives better performance. I suppose the issue could also be driver-side. Certain drivers may not work well with certain features while others may work fine.