Thank you for the answers 
@JayC OCed core at 950 MHz gives me 170+ but the temperature is too high - 82C and I want to keep it <80. Maybe if i improve the airflow inside the box i will be able to keep the core at 950MHz 24/7 but still the difference is not that big...
I'm not from US either. I'm from Bulgaria, Eastern Europe and here local dealers sell 5850 for $288
That's why im currently looking to buy used card and a power supply. And... yeah maybe I will stick with my 5770 + hopefully 5850 as this will be the cheapest mining upgrade.
@JayC OCed core at 950 MHz gives me 170+ but the temperature is too high - 82C and I want to keep it <80. Maybe if i improve the airflow inside the box i will be able to keep the core at 950MHz 24/7 but still the difference is not that big...
I'm not from US either. I'm from Bulgaria, Eastern Europe and here local dealers sell 5850 for $288
That's why im currently looking to buy used card and a power supply. And... yeah maybe I will stick with my 5770 + hopefully 5850 as this will be the cheapest mining upgrade.