i don't think i could get more than 2 coin/day if i was mining with a pool @440 kh
With that hashrate I was getting upwards of 9 coins a day, running 24/7, on a pool.
u're saying u were mining 4,5 coin / 12h
i mined 4 coin / 6h today..
You lose a bit for consistency, that's the way it works.