That is crazy. I use Facebook on a 5 year old MBP with no problems. I have Ad Block Pro and U-Block, but even without them, my computer can handle Facebook just fine.
ublock origin is the only adblocker you need. Adblock Plus does the same thing but is less efficient and lets some ads through by default, and ublock is abandoned.
Don't run two ad blockers, they will just use more resources for no benefit.
