I've got 5 R9 380 cards and after tunning them I'm getting 3000 h/s with 600 W. I'm using SG-miner.
Is it a good resoult for these cards?
I think you are pretty close. You might be able to tweak out 400 h/s more using xmr-stak. Are you doing any over clocking? You might be able to get a little more out of each card. Watch for extra heat if you start overclocking as temperatures will rise.
Happy mining!

Thanks for the advice, I'll try xmr-stak as soon as I arrive home.
The cpu clock is overclocked to 1000MHz and the memory clock to 1600MHz. The temperatures are from 50°C to 57°C depending on the card. Is it too much temperature or can I overclock them more?

The temperature looks ok. Anything over 70°C will cause concern though.