I have two types of sawmills, a Woodmizer LT40 bandsaw sawmill and a chainsaw sawmill. The bandsaw sawmill can make cuts up to about 24" wide and saws fast and efficient. The Alaskan chainsaw sawmill can cut logs up to 66" wide, it is also very portable--take the sawmill to the big log-- and it can also sawmill oddly shaped logs. I also have a Logosol chainsaw sawmill, my first sawmill, which still gets used occasionally to make unique cuts. In December of 2018 I purchased a Lucas Dedicated Slabber which is a large chainsaw bar powered by a 23HP Brigg and Stratton engine and capable of milling a log up to 76' wide and 20' long. This sawmill is very efficient at milling large trees in to nice table tops.
Below are two videos of how I saw the big logs. The one on the left is how I did it from 2009 until December 2018 when I purchased a Lucas Mill Dedicated Slabber, shown on the right. It is almost 3 times as fast and more accurate, not to mention far easier on this ol' man's back.