The jaffrey thing has a version for this.
how do i know if i have the optimized?
it runs really really fast. just kidding. I think there is/was a 64-bit build, and a multi-core build, but I think you should leave it to your OS to figure it out.
Since the optimized builds are using custom code there really is no way to know. You just have to keep track when you install. Putting the custom optimized build in a seperate folder and labling the shortcut works well.