Quick note for anybody using claymore who's hashing speed seems too low.

I'm on an RX480 8GB, was struggling to get over 350H/s, had tried a few miners and drivers.

I randomly tried to screw with the -h perimeter. If you don't put one it, it puts one in for you. I manually put in -h 800, and my hashes doubled to 620H/s. Then I tried -h 1024 and that's moved it to 650H/s. I will keep tweaking, but it's worth messing with if you're going slower than expected!