If your're experiencing lag try the below.
How to allocate more memory for Minecraft:
Normally Minecraft works fine with its defualt RAM, but if you allocate more memory, you can increase performance and minimize fps lag.
Please note: Resource packs require higher than default values and can cause lag. (i.e x128 and above)
What do I have to do?
- Download and execute the new launcher
- In the section "Profile Selection" click on "Edit Profile"
- Under "Java Settings (Advanced), check the "JVM Arguments" box and add/edit into the text area this argument:
Notice: You can't give Minecraft more Ram than you have! Else you will recieve an Error!
- Save this profile and execute Minecraft.
Example Minecraft launcher profile configuration.
How much RAM do I have?
To see how much RAM is free, open the Task Manager and change to the Performance Tab. Look how much Physical Memory is available / free.
Here's a video to help you out if you get stuck.