I had an 18-20 foot pine tree die. It's been standing dead all summer. Today was the day it came down. Mostly.
Took out the Ryobi 14" 40volt and it would not cut through it. I'm guessing the blade is gone. It was bought 'refurbished' off Facebook Marketplace. Which means it was cleaned after it was returned to the store. I used it on small stuff in the past and found it cut slow, but it literally was unable to cut through the pine trunk. I managed to make, with a lot of effort, a V notch about 4' off the ground.
Pulled out the GAS powered STIHL limbing saw, which is clearly not designed to take down a tree with a trunk of 10" diameter but is zipped right through that trunk. Tipped it down with the tractor so it would not fall on my fence. The used the STIHL to de-limb the fallen trunk, cut the limbs and the top 3/4ths of the trunk into bite size pieces so they can be used in the patio fire-pit with the smaller scraps easily hauled down to the burn pile. Then I ran out of gas.
Figured it was time for a break. So as it is, there is a 4' trunk still standing. There is another 4' section of trunk laying on the ground. Pretty much a bunch of debris, small branches, etc are laying on the ground.
Plan to run to Tractor Supply, buy a new chain for the Ryobi saw, come back and try that saw with a fresh blade. Hoping that it works well with a good blade. If a new blade does not DRAMATICALLY improve the performance then I would have to dismiss the saw as close to worthless. But at this point I'm assuming it is just a dull blade.