Restricted to starter edition for up to 72 hours

[Ellay]

Play in fullscreen mode, isboxer makes it's own "windows", this improves fps dramatically. Also I set each screen to run at 20 FPS even on my main one. It plays a lot smoother than if the fps is stuttering around. My PC is about 3 years old with a newer one you may be able to get by setting the threshold a bit higher.

[MiRai]

I thought SLI only worked in full screen mode, it wont help boxers since we use windowed mode. Is this no longer the case?

SLI works in windowed mode as of early 2011.

Play in fullscreen mode, isboxer makes it's own "windows", this improves fps dramatically. Also I set each screen to run at 20 FPS even on my main one. It plays a lot smoother than if the fps is stuttering around. My PC is about 3 years old with a newer one you may be able to get by setting the threshold a bit higher.

If you put your game in Fullscreen mode, it's not fullscreen mode because, just as you say, ISBoxer forces it to windowed mode. You can't multibox multiple games on the same machine in fullscreen mode because one game in fullscreen takes full control of your system's display (and that obviously doesn't work for playing multiple games efficiently).