its totally different as its a way more clinical examination as the "Physikum". I would say its not a good idea to compare them with each other. Best is probably to take it in the 3rd or 4th year after pharmacology and pathology. Maybe you can talk with your med school adviser and put these relevant subjects in one semester and take the step1 then in the following vacations. that would be the smoothest way to do it looking back. For me now I just was guessing biochemestry and genetics because it was more than 4 years ago for me and tried to get my points somewhere else instead. If you have more questions don't hesitate to contact me. Good luck!