Low hashrate on GTX 1060

Today I started mining raven using official tutorial. My GPU is GTX1060 6Gb, unfortunately with Hynix. At the start i was getting max 8.6Mh. Even after overclocking some more to +200 CPU and +400 memory with no power limiting it gives max 9.6Mh. I'm using the kawpowminer software. So here's my question: why is my hashrate so low? Other users online are getting like 20Mh… Is it somehow limited by software? I have latest drivers and HWMonitor shows 100% GPU usage all the time. Does the pool that I'm connected to have any impact on performance?