Greetings,

I am trying to use DirectX to query available video memory.
These are the numbers I get:

For my 256MB GeForce 6800:
GetAvailableVidMem: total = 256901120 free = 256852992
AvailableTextureMem = 448790528
That seems OK.

But, for my 128MB ATI FireGL3100 card:
GetAvailableVidMem: total =
654180320 free = 654180320
GetAvailableTextureMem(): 654311424
That's around 624 MB!

I am only interested in knowing whether the card is a 64/128/256 model. I don't care how much is available for use etc.

thanks,
Maniam

My code:
------
LPDIRECTDRAW lpdd = NULL;
LPDIRECTDRAW7 lpdd7 = NULL;
DDSCAPS2 ddsCaps2;
DWORD dwTotal;
DWORD dwFree;
HRESULT hr;

ZeroMemory(&ddsCaps2, sizeof(ddsCaps2));
ddsCaps2.dwCaps = DDSCAPS_OFFSCREENPLAIN;
hr = lpdd7->GetAvailableVidMem(&ddsCaps2, &dwTotal, &dwFree);

g_pD3D = Direct3DCreate9(D3D_SDK_VERSION);
D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory( &d3dpp, sizeof(d3dpp) );
d3dpp.Windowed = TRUE;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &g_pd3dDevice ) ) )
{
return E_FAIL;
}

DDSCAPS2 ddsVidMemcaps;
ZeroMemory(&ddsVidMemcaps, sizeof(DDSCAPS2));
ddsVidMemcaps.dwCaps = DDSCAPS_VIDEOMEMORY;
int AvailableTextureMem = g_pd3dDevice->GetAvailableTextureMem();

Have a look into the DXDiag interfaces - they do what you want. In the latest NV SDK there's a sample app that does this exact thing.

*edit: err.. I just remembered that the "latest SDK" isn't publicly available yet, and I can't remember if the previous version has the example (quite likely though). If it doesn't, NVSDK 9 should be out very soon.