minecraft-java-editionperformance
I'm a happy Minecraft player. I place my blocks, mine my coal, and generally nobody gets hurt. Lately though, those mean creepers have been sneaking up on me from behind, and killing me. Why? Because my framerate is so darn low.
Adjusting the graphics option (Fancy to Fast) and the render distance help, but they are not enough. I have seen mention of outside optimizations and programs that people have made/used. What hacks, tricks, and mean mods can I use to improve my Minecraft FPS?
Yes, I've done this with a much less high-powered PC and about 8 or 10 users connected. It worked fine.
The biggest problem with Minecraft servers (apparently) is that if your players explore too far, your memory footprint will get ridiculous at some point. I didn't see any problems in this area, though - most of my players stayed near the spawn for the most part.
Update: According to Notch's blog post about changes coming in 1.6, the torches-on-fast-leaves bug is getting fixed:
This means that monsters can no longer spawn on leaves, either, as they are always considered transparent, even when using Fast graphics.
Monsters can spawn on any solid, non-transparent block which is at light level 7 or lower.
Signs, torches, rails, and the like are ignored when spawning monsters; they'll spawn on the block underneath just fine. This is why one-block-wide railways need to be lit.
Transparency means whether or not light passes through a block rather than whether you can see through it. Half-blocks, doors, stairs, and glass all count as transparent and prevent monster spawning. Leaves, oddly, count as transparent only when Fancy graphics are enabled. An easy way to test a block for transparency is to try placing a torch or sign on it — neither can be placed on transparent blocks. (Meaning that torches can be placed on leaves with Fast graphics, but not with Fancy.)
Torches put out light level 14, so monsters can't spawn within 5 blocks of a torch orthogonally or 3 blocks diagonally. If you put your torches in a diamond pattern, they can be up to 9 blocks apart, but it's best to move them closer than that on uneven terrain. (I use 5 myself.)
If you like, you can actually torch your treetops by changing your graphics to Fast, placing the torches, and switching back. Your torches will stay rooted, even though you wouldn't normally be able to place them that way. Personally, I think it makes them look rather cheerful. :-)
Best Answer
There are a number of mods that claim to improve FPS in Minecraft. My experience is limited to OptiFine (an updated version of Optimine from around version 1.2) on 1.8.1, but I do see a very significant improvement in my FPS. Although it's a bit non-specific, I have seen my FPS on a Mac go from completely unplayable to very smooth.
OptiFine (Minecraft Forum Link) reworks a number of rendering details to improve Minecraft performance (+20fps). Many people go crazy about it on the forum, others say that it just doesn't work so YMMV.
Last I heard, Notch was actually including some of these optimizations into Minecraft proper.
Keep in mind that any Minecraft mod that's not a skin requires you to patch the Minecraft code itself and thusly may not be compatible with other mods or your Minecraft version.