How to play Minecraft 1.6.2 with server and client on the same computer.

Steps to reduce rubberbanding (lag where blocks repop after being mined or Steve retakes the same steps again) in Minecraft version 1.6.2 while running the client on the same computer as the Minecraft server. This may work on other versions of Minecraft, but I have not tried them.

Summary: Changing the processor affinity is easy and seems to reduce the input lag and rubber-banding issues on this computer. The change is not permanent and in no way should it ever cause harm to the computer.

1. Install the correct version of Java (32bit or 64bit). TIP: Match the OS you have installed.
2. Install the recommended Minecraft server installer from http://files.minecraftforge.net/minecraftforge/.
3. Install the Minecraft client files (these should already be installed if you've been playing Minecraft!).
4. Create a shortcut on your desktop to start the server. TIP: Try the shortcut "C:\Windows\System32\javaw.exe -Xmx512M -Xms512M -jar C:\Minecraft\minecraftforge-universal-1.6.2-9.10.1.859.jar -server -XX:+AggressiveOpts"
5. Create a shortcut on your desktop to launch the client. TIP: Set the profile options to "-Xmx1G -Xms1G -XX:+AggressiveOpts"
6. Start the server.
7. Using your favorite program (I use Task Manager), change the processor affinity on javaw.exe to 0. (Keep note of the PID).
8. Launch the client.
9. Using your favorite program (I use Task Manager), change the processor affinity on the second javaw.exe to 1.

Your results may vary.. Let me know!

[Update 9/19/2013] Removing the flags that the minecraft forum on Reddit said contradicted each other and did not help has reintroduced some weird block repopping side-effects. I'll have to add the flags back one at a time and do some more testing.