Raker depth and pitch seem to have more to do with clearing chips than other factors I have found. .404 may cut better than 3/8 even if slower chain speed is a result. 1/2 chisel cuts much better, and sometimes faster, than .404 chisel on powerful geardrive saws. My 125 with 50" bar cuts better than my 101b that would need the rakers down so it could bite properly. The 101 just spins the chain much faster. Long bars in big pitchy fir have more of an issue of pitch and chips building up between the bar and chain on the underside of the front of the bar. It can easily lock up everything with the chain up to 1/4" or more separated from the bar. An over abundance of power and a bar that exits the far side of a log help against this buildup.