This thread is to help all of you people will sucky PC's get the best out of minecraft!Modifications to your Minecraft Client!Various code modifications have been written to optimize how Minecraft manages chunk queues and (some) rendering. They are actually pretty simple to apply. Anyone able to use an archiving program (like 7-Zip) will be fine.Modifications unfortunately need to be updated and re-applied with every Minecraft update, so expect times when modifications will not be available after Minecraft updates.Getting started:First of all navigate to your Minecraft storage area:This can be done by entering path %AppData%/.minecraft in the Windows Explorer address barMake a folder called mods to store downloaded modification packagesEnter the bin folder, there should be a file called minecraft.jarMake a copy of minecraft.jar as a back-up (although you can just delete it and start Minecraft to get an original version back)Go back from the bin folder back to the .minecraft folderNow download the following modifications into the mods folder:OptiFine:More efficient chunk rendering queueFaster text rendering supporting UnicodeFewer expensive screen clearing operaitonsBetter chunk drawing codeBetter TNT explosion handling (less lag)Useful OpenGL error message when the game rendering code crashesNoSoundLag:Minecraft 1.3 involved a lot of internal changes to reduce the amount of server code duplicated by the client. One unfortunate side effect is that if you're on a noticeably laggy connection, your block placement and footstep sounds will lag as well. The server controls those sounds now, not the client.A proper fix will involve changing both the server and the client, which doesn't appear to be coming from Mojang. Maybe in 1.4.In the meantime, this client mod exists. It does not require any server-side modifications.Make sure in install the mods in this order: OptiFine then NoSoundLagTo apply each modification follow these instructions:Open minecraft.jar with an archiving tool (7-Zip recommended)Open a modification package with an archiving toolSimply drag the class files from the modification package into the archiving tool that has minecraft.jar openSay yes to overwriting filesImportant for players to delete the folder called META-INF (only needs to be done once, important that servers don't do this)Start up Minecraft, and hopefully your game will run smoother now. Some users claim 20-40 FPS improvements, though others still have to use tiny rendering distance and fast graphics to see any improvement.2. Upgrade Java Run-time Enviroment to 1.7I've seen various claims of it having good performance improvments, and can now vouch for this myself. Using tiny render distance with fast graphics gives me 800+ FPS, while using far render distance with fancy graphics gives me around 200-300 FPS (without the limiter on).A version of JRE isrequiredon your system already as the installer is actually in Java.64-bit users don't actually need the 32-bit build as well as the 64-bit build if you're only using it for Minecraft, it's optional. You may want it for other apps to use.Installation steps for JRE 1.7:Download JRE 1.7 (either 32-bit or 64-bit or both)Open a command prompt in Administrator mode (Vista/7 only)Execute: Code: java -jar path\to\jre1.7.jar(actually replace the -jar location to where your JRE 1.7 download is)Select the Java folder within Program Files as the installation destinationA folder called jre1.7.0 will be made inside the destination you choosePick Program Files (x86) if you're using the 32-bit JRE 1.7 on a 64-bit version of WindowsI used this guide a couple of days ago to get JRE 1.7 on my portable Ubuntu.Making a Minecraft shortcut to use JRE 1.7:Download the Linux/generic JAR Minecraft launcher and put it in your user folder somewhere, as you won't be using the EXE Minecraft launcher for JRE 1.7Make a new shortcut to Code: %ProgramFiles%\Java\jre1.7.0\bin\javaw.exeand name the shortcut MinecraftEdit the properties of this shortcutSet the target to: Code: "%ProgramFiles%\Java\jre1.7.0\bin\javaw.exe" -server -Xmx1024M -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=2 -XX:+AggressiveOpts -cp "minecraft.jar" -jar "minecraft.jar"Set the starting folder to the location of the Linux/generic JAR Minecraft Launcher you just downloadedUse this shortcut to start Minecraft on JRE 1.7 Code: %ProgramFiles(x86)%can be used if you're running 32-bit JRE on 64-bit Windows.Please do share your performance findings compared to a previous version of Java. You also probably won't need to force vertical sync in your graphics drivers as the frame rate limiter appears to do a better job when running on JRE 1.7.If your JRE claims the server JVM is missing either download and install JDK 1.7 or remove-server from your command line. The server JVM generally runs faster than the client JVM, though takes a little longer to start and will want more memory.Other common performance tips:Stating the obvious:Running the javaw.exe process that executes Minecraft code at above normal or high priority (do not use real time)Lowering the Render distance and changing Graphics to FastDon't maximize the Minecraft window -- leave it at the original sizeApparently turning off the game sound and music helpsUse a low intrusive anti-virus program (such as Microsoft Security Essentials or Avast)Clean up rubbish and remove intrusive start-up processes with CCleanerDefragment your system storage with a good utility (such as MyDefrag or UltraDefrag)Use GameBooster while playing Minecraft, it turns off all the clutter while you are gaming.If you are to lazy to install mods the manly way you could use Magic Launcher, you can find a video on how to use it HERE.More tips are welcome!