Increased system requirements

I don't know if this is intentional but I can no longer play on my system lag free and the game is taking nearly all of my processing power. I don't have the fastest computer(it's kind of old) but I used to be able to play on fast graphics, normal render distance, and power saver without any problems. Now the lag is so bad it's unplayable. I hope this isn't intentional and gets fixed or I won't be able to play one of my favorite games anymore as I don't have the money for a new computer.