This is exactly what you shouldn't do; compare yourself to others.
I might say I study 1 hour per night, but I get a lot done in it. Or someone else might say they study 9 hours per day when most of it is spent browsing snapchat while they 'negotiate physics notes'.
In reality, I do my home well, and I ensure I understand the CURRENT topic (wayyy more important than revision of basic conceptsin 5th year). Then occasionally I read the exam papers, check out some questions. Sometimes do a few exam paper questions on the current topics. I study very well for the current topics, ensuring I receive a H1, or very close to it, in all class tests.