Hi! I've met some interestiong problem at one notebook with radeon video. Abstract: I have engine which uses direcx to quickly display large texture within some client window. I paint some graphics into bitmaps and then transfer raster to some texture and pass it to video to draw it and shift it and so on. So, ofcourse there are many other windows in my app, and some of them are transparent (half-transparent) and appear above my directx-window like some tool balloons (as same in Office). Or there are few information windows also may appear above dorectx-window with picture painted. So with some hardware it works perfectly fast, but on some machines it is SO SLOW when youre dragging transparent window above directx-window. It refreshes line by line on display.. like 20 yrs ago pc :) Sometimes you may not drag transparent window, but if one is above directx-window, all paintings and refreshes of directx-window will be incredible slow! Here is question: does somebody meet this problem or solved it or have same problems??? I hope there will be some special D3D flags to solve this problem, but i dont know where and which... PS: i tested some well-known programs which use same technique and founded exactly same problem!