THIS IS NOT AN ISSUE WITH YOUR COMPUTERS!!!!!!!!!!!!!
SOLUTION: Okay guys, I know you are all very upset. So was I, trust me. My computer is dang decent and this was blowing my mind! Well guess what? You don't have to buy a new set-up IF YOU MEET this one simple condition......
Do you lag the hardest inside buildings? If you say yes, then delete your client completely and re-download it. Problem solved! Just like magic! Crazy huh? You're welcome.
This will fix your issues. IF you do not lag harder in buildings, then I regret to inform you that something is wrong on your end.
Enjoy! & Happy Holidays... send credits to Dusk on The Crucible Pit server as a thank you. lols