Anti Aliasing. It's a very resource intensive graphics feature. It attempts to eliminate jagged edges, and smooth them out. There are also diferent levels of efectiveness.
2x being the lowest AA mode. 4x is even better, etc.
You aren't gonna have enough . My advice is Save up some more cash.
Edit 1 : With 350 you can build a decent performer. Since you already have some stuff. I'll see what I can manage , just don't expect anything max at 1080p.