[GUIDE] Fixing lag and improving framerate

[sf17k 4]

Today I struggled to get a playable framerate in TFC on my modest computer setup, and finally had some success. In Minecraft, lag comes from a lot of different sources, and I experienced just about all of them. There's a lot of threads about lag problems, so I figured writing a guide about it might be helpful.

My system specs, for reference:

Windows 7 32-bit

3GB RAM

Athlon 64 X2 Dual Core 4000+

GeForce 8600 GT

Disclaimer: What's written below is what worked for me on my machine. You might get different results (or break your system).

There are various sources of lag. You might have to fix all of them. Here are the ones I found, how to identify them, and what to do about them:

32-bit Java

Symptoms:

• Setting Render Distance to Far shows a warning
• Game doesn't launch when memory limit is set higher than 1024 MB

Solution: If you have a 64-bit OS, install or reinstall 64-bit Java. If you did that but minecraft still uses 32-bit Java, try this.

If you're on a 32-bit OS, there's nothing you can do about this, except upgrade. Minecraft doesn't like 32-bit Java. Still, I was able to get TFC playing at smooth framerates using the rest of the tips.

General Minecraft slowness

Symptoms:

• Low FPS
• Frequent stuttering

Solution: Get OptiFine. It's a great performance-improving mod. I use the TFC launcher so I installed OptiFine with this method. If you don't use the launcher, you have to make sure you get the version that's compatible with everything and install it right.

Once installed:

• Go into Options > Video Settings
• Set "Chunk Loading" to "Smooth" (UPDATE: I discovered that setting this to anything other than "Normal" can cause crashes)
• Click "Performance..." to open a submenu
• Turn on "Smooth World", "Lazy Chunk Loading", and "Dynamic Updates"

This is what worked for me. Your mileage may vary with regard to these settings, so play around. You can set "Chunk Loading" to "Multi-Core", but this didn't do anything on my dual core (I think it's for 3+ cores). I don't know how important the other settings are, I just turned them on for good measure.

I also had to lower the render distance to Short+32 to get good FPS, but that depends on your system.

Java Garbage Collection

Symptoms:

• Game periodically pauses for about a second at a time

Solution: Add -Xincgc to java's command-line options.

Garbage collection is a really technical thing that I don't expect you to understand. (Though if you do, here's more info.) Here's what I did to make this solution work with the TFC launcher:

• Go to Control Panel > Programs > Java
• Under the Java tab, click "View..."
• There should be a confusing line with an empty space under "Runtime Parameters". Double click that space and enter this exactly: -Xincgc

Note: This method changes the setting for ALL java programs. Which shouldn't be a big deal, but undo it if it breaks some other java app. I don't know of a better way to do this using the TFC launcher. Other methods for running TFC may allow you to add -Xincgc to minecraft's options directly.

Out of Memory

Symptoms:

• After a while, the game repeatedly freezes for long periods of time, until it becomes unplayable
• The file output-client.log (in the minecraft dir) shows Out of Memory errors
• Most obvious: Minecraft crashes and shows an Out of Memory error

Solution: Increase memory limits in TFC launcher settings or with command-line options. Keep it less than the amount of memory in your system. 3072 MB should be good, if you have more than that.

On 32-bit, set both the min and max to 1024 MB. If you set it higher the game will not run. You will probably still get some freezing, however. Like I said, Minecraft doesn't like 32-bit. When it freezes, press Escape ONCE and wait for the pause menu to show up, then click Save and Exit and restart the game. This is what I do. It happens rarely enough that I'm willing to live with it.

Notes

There may be sources of lag outside of Minecraft, like if your system is running too much crap or something. These aren't covered here.

The memory usage shown by F3 doesn't seem useful for anything. If it's hovering around 90% that's bad, but you can still get Out of Memory errors when it shows low percentages (strangely).

On multicores, if you're still having trouble, one thing to play around with is right clicking the java process in task manager, click "Set Affinity", and try various combinations of allowed CPUs. (This once helped me identify a strange issue with desynchronized core clocks where the game would randomly blip forward in time...)

Hope this helped! Post improvements or corrections if you have any.

[PieisJesus 0]

Hey,

Whenever I try to open the Java part in Control Panel>Programs, its says "The requested operation requires elevation"

Then it says where the Java application is saved.

I went to the Java application, and it was already given administrator rights.

How can I stop this?

[sf17k 4]

Whenever I try to open the Java part in Control Panel>Programs, its says "The requested operation requires elevation"

Solutions I've found online: Reinstall java, or disable User Account Control (maybe you can turn it back on afterward if you want to).

[PieisJesus 0]

I have already re-installed Java, and that didn't work, and i tried the website you gave me, but that is for Windows Vista, and I have Windows 7.

Do you know how to disable UAC on Windows 7?

Thank you.

[EDIT] Never mind, I have figured it out. Thank you.

[tyriael-soban 12]

32 bit java on Windows is capable of supporting up to 1600 Mb Virtual memory at the most, Minecraft is only using the memory its programmed to use, which is 500-1024ish, depending on how much you have on your system board, unless you cross out of the initial memory allotment your computer will only show minecraft as using 500ish.

You can write a msdos batch file to up your memory limits even if youre on a 32 bit system, XP OS should only consume about 512-1024 Mb of ram, which leaves you with 2-2.5 Gb spare, but again, only up to 1.5 Gb for a jre's virtual memory on 32 bit windows.

http://sinewalker.wordpress.com/2007/03/04/32-bit-windows-and-jvm-virtual-memory-limit/

[MinecraftDude_99 0]

Do you have any idea how to install optifine without the launcher???? It no longer exists.... Thanks!

[Kittychanley 1,002]

Do you have any idea how to install optifine without the launcher???? It no longer exists.... Thanks!

 

Optifine has simplified so that if you are using forge you just put it in your mods folder like everything else.