I'm not able to get my Sapphire Nitro 4gb RX 470 to hash faster than 32sol/s

I've tried tweaking the clock and memory speed, running win7 64bit and latest crimson.  Can anyone give advice?  I will try flashing the bios next, but I'm curious what others are doing that I'm not.  I see some people getting 40-45 and I'd like to see their bat files if possible.

EDIT:  I'm also wondering what is the best value right now, is it the RX 470 4gb, the RX 480 4gb, or the RX 480 8GB.  It kind of looks like the 470 is the winner for dollars vs hashrate vs electricity consumption?  Are they good for mining Ethereum also?