In game memory performanceFollow

When I am playing wow I usually keep an eye on my performance info using performancefu. I noticed that my memory usage is in bold red all the time running 50-60. I thought when i first started playing WOW you could allocate a certain amount to memmory for your addons. No I cant find such place to change now. How do you address the memory being used in game other than not using addons? Sees like auctioneer, gatherer and mobboss) are the biggest slurpers of my memory and it would be hard to play w/o them.