My game supports both 16-bit and 24-bit mode. To change from one mode to the other, all I do is change the call to

LPDIRECTDRAWSURFACE->SetDisplayMode

. And the game runs much faster in 16-bit mode than in 24-bit mode.

If your game runs at 30 fps in 16-bit mode, it''ll run at 20 fps in 24-bit mode, and probably even 15 fps since some operations can''t take advantage of WORD-alignment.

~CGameProgrammer( );