there is no problem with the miner. In the batch file there is tls or tcp parameters which can affect your miner tremendously. with my 3 570s and a single 580 I'm getting between 25-27 mhs. The question is what pool are you mining and what settings are you using in the miner? I didn't use the asm option because my pool didn't support it. I didn't use the TLS option because my pool didn't use it. My biggest problem with using amd cards in general are the buggy drivers that constantly change my settings (in wattman) especially when I'm mining nicehash. The only setting that stays stable for me is the -15% power setting and the temp setting. everything else tends to get wonky.