year 9 revision???

I am in year 9 and I am starting some of my GCSE courses (English (Animal Farm) Science (working towards getting a 6+ in the summer to do triple) Geography, German etc) but my school puts a lot of emphasis on exams and revision. I started the first week after Oct. half term for the exams (dec 6 - 12). I am a straight A student and I hope for 9s in my GCSEs. Currently I've been doing an hour per night, two sometimes. Is that enough for year nine?