I've mostly heard those types called BuzzSaws or Saw Rigs. Have heard them called Cordwood saws and some other things too, but Saw rig or buzz saw is most common to me. Many run/ran off tractor PTO, or way back even ran off long belts connected to car wheels(jacked up) or other machinery. I've seen electric powered ones, small engine powered, and even one built on a vehicle frame with a Ford straight 6 for a power head......that one was trailerable and everything.
I've got parts to build one or two of these, but they're older style(not much safety on them) but need to put them on a frame and mount a power/engine of some sort. Hope to get to it someday. But I've just kept cutting up my small stuff right in the woods and hauling it in with the rest of the load. Had some limb piles here until this year, but cut up the last one with the electric chainsaw this summer.
Do have an old saw buck as well, but don't tend to use it much unless I do have tons of small limbs or slab wood. But again, I cut most stuff right up with the rest anymore and rank it among everything else too. That way, have large, small, medium, all sizes of wood in every rank.....or try to at least! The small stuff is great for starting fires.
There are pros/cons to all these methods or contraptions. The buzz saws can be VERY dangerous, but are one heck of a tool as well! All these extra things take up room one place or another though. But always good to see how others take these tasks on!
I hate the sound of those things! :angry2: 
