IDirect3DDevice9::GetAvailableTextureMem()

Has anyone used this function or know any more information about it other than is what is available in the SDK?

I've been using it to report video memory consumption but the original numbers prior to any allocations just don't match up with the manuf. numbers for the card. Does this function also include the PCI and AGP 'aperture' sizes and thus counts that as available video memory?

Apparently it does, and the workaround is to use DirectDraw to probe for it instead.

You can also get the total video memory from the Win32_VideoController class in WMI. I think that's quite a lot of native C++ for one piece of info though, especially one that's dependent on WDDM drivers in Vista+.