The water example has 280 FPS.
All the tiles have the size 32x32 and my resolution is 1024x768 with 16 bit.
The texture format is D3DFMT_A8R8G8B8.
In my game you can zoom from 50% up to 200%.
But when scale < 70 or 80% the FPS go down fast. Before I used bigger tiles(64x64) and the game ran much faster. So I thought a big image would solve the problem.

If you have time, you can download the game with soure code on
http://mitglied.lycos.de/crazyhunter...oad/cobal4.ace
The Engine is in the unit UPowerDrawEngine.
Thanks for your help so far!