Lazarus screensaver

[Imants]

I don't know is even this is lazarus problem or not, but
I am trying to create screensaver for winnows in OpenGL (I use windows 7 64 bit and lazarus 64 bit).

The problem is when I change file extension from exe to scr my application enormously slows down. When I run it as exe it takes only about 1-3% of my CPU. When I run it as scr it takes about 13% CPU which is only one core (I have 8 cores) and as it is only using 1 core it works very slow.

Does someone run in that kinda problem and know why it is happening?