well, i disagree with the majority of the previous advice. i have personally milled over 20,000 bd.ft. mostly hardwood, oak and maple, and i can tell you one thing. you need SPEED, lots of it, and torque. i have 29 vintage saws, all 80ccs or bigger. lots of big macs, including 2 sp125's. they all suck at milling. yes they have more torque, but milling with a chainsaw is a slow process, at best. you try milling with a 250 mac, or any of the others of that line, and you are gonna be pushing the saw for 15 or 20 minutes wide open to make one cut. the 125's will mill, but don't try it in summer or you'll have chunks of aluminum coming out the exhaust. try wrestling one with a long bar and a mill attached. my 066 is 50% faster than any of them milling, hard or soft. if the logs are bigger than about 20" or so, and hardwood, then i break out the 088, which doesn't spin as fast as the 066, but is much faster than any vintage saw. i prefer the 066, and use it 90% of the time, because of the higher rpm's, and it is better on fuel than the 088.