I tried to mine ETN using RX580 in Gateless gate sharp..
Why it show actual hashrate only around 300 H/s while in approximate hashrate it can reach 800..
Is there any item I should modify to get the max hashrate?
What do you mean "actual hashrate"? I use GGS for cryptonight on ETN. Speed of cryptonight in miner same as allways. RX 580 800+ h/s.
Maybe you mean hashrate showed on the pool where you mine? In this case you must know that pools shows hashrate calculated from accepted recieved shares and difficulty on wich they was finded. If your pool shows recieved hashrate less then in miner it's a pool problem, not miner. Check pool diffeculty, maybe it too high for your rig. Try to use another port number from your pool with less difficulty. Pool can stale your shares. Try another pool.
And onother one thing - for compare actual speed from pool you must take it for long period of time. F.e. 12 hours or 24.