Dual Monitor Issues

[Smegboy]

Hi, has anyone had any experiences with a Dual Monitor environment?

I have developed a 2d Application with Delphi-X which runs at around 20 fps (intentionally) at approx 2%cpu time.

If I drag it onto the second screen it bolts to 45%

Another strange factor is if the application stays on the primary and the task manager moves onto the secondary interface, my application cpu time still jumps.

Has anyone else had any experiences with this. :cry: I need to resolve this very quickly.

Regards,

Matt.

[Useless Hacker]

If they are on separate graphics cards, this could be because the backbuffer is on the primary card, and so is having to be copied to the secondary card. But I have only ever used one monitor, so I don't really know. I don't think DelphiX will allow you to specify which adapter to use, it probably just uses the default.

[Smegboy]

Thanks for the response.

No this is on a dualhead video environment.

Matt.

[Clootie]

You can't do anything with DirectX7 interfaces to resolve you issue. It's designed to work like you see. When you move your output window from one device to another DirectDraw start some kind of emulation - it get rendered back-buffer surface back to system memory and later blit's it from system memory to "another" device primary surface. This is described in DX SDK documentation.

Workaround I've used long time ago it to create two identical D3D devices on different monitors and manage output by yourself (limiting blitting to single monotor when window is dragged).