is screenshotting by DirectDraw faster than GDI way?

just to save some time, probably anybody tried this or saw somewhere related info.

asking about DirectDraw and not about DirectX because I need to support Win2000 and up, and 开发者_如何学运维I cannot install DirectX on target PC

tried capturing by Direct3D and compared with GDI way. Results are not unambiguous. On my Win7 x64 with rather good video card D3D way shows ~2 times performance boost. On my WinXP 32bits laptop with not-integrated but old video card D3D works much much much longer. On another WinXP (I don't know any hardware details) D3D works almost 2 times slower.