Hello everybody!

I'm relatively new to mining, but I intend to make 2 or 3 rigs with GTX 1060 (since it's like 2.5x cheaper than gtx 1070 in my country). So far, the cheapest I can get is the Gigabyte GTX 1060 Windforce 2 OC 3GB with hynix RAM. This VGA mines with 15mhs out of the box, and up to 19mhs with clock (Core +170/ Memory + 1000, 80%). Currently I'm using the newest driver: 385.41 on Windows 10 64bit. The card is on the main PCI-E slot.

I've checked all the info I could get about gtx 1060 3GB and as I can see many reach ~20mhs out of the box, and few of them reach 25mhs with clock. None of them is Gigabyte though.

So my questions are as follows:

1.) What could be the reason I get so low mhs ?
2.) Did I make mistake buying Gigabyte, though it has Hynix memory.
2.a) If I did mistake with Gigabyte, what brand would you recommend me?
3.) Could you recommend any clock rates / bios that might boost a little the mhs?
4.) Could it be the Driver problem?

I'd appreciate any help and information I can get

P.S: Im using Claymore Dual miner v.10 - Ethereum + Decred