User blog comment:SpeedySC/Does it lag?/@comment-216.232.195.113-20150204022945

It's possible to reallocate more memory to Minecraft. In the launcher, click the "edit profile" button underneath your selected profile. At the bottom of the editing screen will be a section titled "Java Settings (Advanced)" check the box beside "JVM Arguments", and change the first statement on the right from -Xmx1G to -Xmx2G. This allocates an extra 1 gigabyte of RAM to the selected Minecraft profile, and can help improve performance.