Hi Thirith. Rogue Leader is a demanding game even for a great CPU like yours.
Firstly, get the latest dev version from the download page and see if that helps, and select OpenGL as the graphics backend, this has worked best for NVidia cards for me in the past.
If the game is still slow for you on the latest dev build, try using the CPU clock override function located in, Config => Advanced. Start at about 80% and work you way up or down from there, monitoring how it effects the frame rate.
It's unlikely the game will still be running slow after that, however there are some more tricks you can use if you need too.
Give these suggestions a try and let us know how you go.
Al
Firstly, get the latest dev version from the download page and see if that helps, and select OpenGL as the graphics backend, this has worked best for NVidia cards for me in the past.
If the game is still slow for you on the latest dev build, try using the CPU clock override function located in, Config => Advanced. Start at about 80% and work you way up or down from there, monitoring how it effects the frame rate.
It's unlikely the game will still be running slow after that, however there are some more tricks you can use if you need too.
Give these suggestions a try and let us know how you go.
Al
Win 10 Pro x64 - I7 4770k 4.3GHz - GTX580 3GB - 16GB 2133 Gskill