There are a few things you can do to help your PC handle Minecraft better, here's a few.
- Installing optifine usually gives a noticeable FPS increase :http://www.minecraftforum.net/topic...d1-fps-boost-hd-textures-aa-af-and-much-more/
- Always install the latest Java version from https://www.java.com/en/download/manual.jsp This will usually increase Java performance, as well as patching you against security vulnerabilities in the software.
- In your Minecraft launcher press "Edit Profile", tick the box next to "JVM arguments" and add -Xmx1G to the box.