wat ever may be the time that u prepare prepare effectively and concentrate on studies
the final outcome doesnt depend on how much time u studied but on how effectively u had learnt the conceplts
studying for two years is single step and putting ur efforts and writing in the final exam is one step
i used to go to college from 5am to 8 pm (two hours relaxation included)and them read from 9pm to 11 30-12
read as much as u can but check its effectiveness
practise thoroughly
even in my case i had messed up in the final exam and ended up with mere 265+
ok then all the best