I used to do a 3 day split twice in a week: Chest/Shoulders/Tri's on Monday and Thursday, Back/Biceps on Tuesday and Friday, and Legs on Wednesday and Saturday.
I grew like crazy for about 2 months, strength didn't get any better, but then I guess I entered the land of overtraining because I didn't progress ANY for about 6 months until I switched to a 4 day split, and later to a 3 day split. Once I did that, I grew like mad for about 6 months (i.e. 40lbs weightgain, about 90lbs on bench, etc.). Now, I'm stagnant again because I haven't had my head in it entirely for several months.