So, I often find myself converting 1080p videos from one format into another (typically an Apple proprietary format into .mkv or .avi) but I'm having trouble finding a decent program that does this. I have 2 GTX 580's so I'd REALLY like a program that can leverage these against the conversion as it would go MUCH faster. I'm okay with paying for the software if it works well but I also know that there are a lot of excellent open-source utilities out there...whatever works best... I'm having trouble finding reliable reviews on these program so I'm hoping the Tom's community can help me out.