I have about 200 pine logs that are well seasoned, but these are proving to be a challenge. These logs measure from 20'' to 40''. Tried 3 different saws thinking that chain speed mattered. Chain types do not matter. So I am puzzled what to do. The problem is that short of carbide plated chain which is about $3000 per loop are the knots. The saw always has to parallel with the knots or a chain will not last more than 5 seconds or less. Thanks