@girino I am mining with a AMD 6870 and have tried every GPU miner by you and Gigawatt 
I've found out that Gigawatt's v 1,5 is the fastest one for me. With that one i mine at about 14650 khash. All others are like 10000-14000 khash. Can you tell me if this sounds right or if i have some settings wrong? I don't really understand what the stepsizes are or the -a. (Have tried different settings) 
The reason I'm wondering is why the newer GPU miners are slower for me
I've found out that Gigawatt's v 1,5 is the fastest one for me. With that one i mine at about 14650 khash. All others are like 10000-14000 khash. Can you tell me if this sounds right or if i have some settings wrong? I don't really understand what the stepsizes are or the -a. (Have tried different settings) The reason I'm wondering is why the newer GPU miners are slower for me