This post is currently applicable to Minecraft 1.5 I've been getting a lot of questions about lag in Minecraft so I figured I'd help people understand more about the types of lag and the solutions to it. Client lag Client lag is by far the most obvious and consistent type of lag. There is usually very little that can be done about this. Common symptoms of client lag are: Low count of frames per second (as displayed in the debug screen as FPS) Game freezing Mouse and keyboard responsiveness is slow I won't bother explaining all of the symptoms as they're rather obvious to most, but try running through this checklist to help squeeze out a little extra performance on your computer: Solutions In your Options Menu, click "Video Settings". Set the following video settings: [table] [tr] [td]Graphics: Fast[/td] [td]Render Distance: Normal, Short, or Tiny (depending on how powerful your machine is)[/td] [/tr] [tr] [td]Smooth Lighting: Off[/td] [td]Performance: Max FPS[/td] [/tr] [tr] [td]3D Anaglyph: Off[/td] [td]View Bobbing: Doesn't matter[/td] [/tr] [tr] [td]GUI Scale: Doesn't matter[/td] [td]Advanced OpenGL: ON*[/td] [/tr] [tr] [td]Brightness: Doesn't matter[/td] [td]Clouds: Off[/td] [/tr] [tr] [td]Particles: Decreased[/td] [td]Server textures: Doesn't matter[/td] [/tr] [tr] [td]Fullscreen: Off[/td] [td]Use VSync: Off[/td] [/tr] [/table] * This option may not be properly supported by your video card. If your performance suffers, simply turn it off. Network lag Network lag can happen in two majorly different ways: The lag can be on our end: Server network lag is most prominent when our server's bandwidth cannot keep up with demands. This should only happen when our ISP is having issues routing Internet traffic properly. Occasionally, our server is under attack from hostile computers controlled by a botnet master (better known as a script kiddie). However, the lag is more likely to be on your end: Client network lag usually occurs when your Internet cannot keep up with the demands of playing Minecraft on a server at the time. This could be a bad route from your computer to our server or you simply don't have enough bandwidth available to stream all of the Minecraft data. Common symptoms of network lag: Players and mobs are constantly stuttering Chat is sluggish to display your messages after you've sent them Blocks continuously reappear after mining them Items on the ground are slow to get picked up Placing or breaking blocks in a protected zone are not reverted immediately Opening chests is slow The game in general slows to a stuttering crawl. Solutions If your connection to Legion Servers is normally quick and responsive, troubleshoot your home connection. Try the following: Make sure you're not downloading or uploading large amount of data. Make sure no one ELSE is downloading or uploading large amounts of data. Try running a Pingtest and a Speedtest. If the results are bad, continue troubleshooting. If you're behind a router, try restarting it. Restart your cable or DSL modem If you're a bit more tech-savvy and your connection is still bad, try utilizing some networking tools such as ping and traceroute. Effectively using these tools are out of the scope of this post, so I will not explain them here. Server Tick lag Server tick lag occurs when the server is too overloaded due to the amount of players, mobs, redstone/lighting bugs, or programming errors. This doesn't happen (often) on Legion Servers ;] Common symptoms of server tick lag are: All players are frozen or jumpy All mobs are frozen or jumpy. When the freeze stops, the mobs will all move really fast. Redstone contraptions are jittery Physics for falling blocks are slow to react Blocks appear to break, but do not drop anything. In an extreme cases, chat will freeze (programming issue crashed the server, and your game hasn't figured that out yet.) Solutions Unfortunately, there's usually nothing you can do about this type of lag. It is an issue on our end. Solving this usually involves a long process of us reading through various stack traces, bits in pieces of the internal Minecraft source code, and examining any trouble-causing plugins. Tick lag will also happen when a user tries to push Minecraft to the max -- an example that works on many other servers is collecting hundreds of chickens in the same block. This causes the Minecraft Server to do lots of intensive calculations for each and every chicken. In this specific case, collision detection, path-finding, and re-calculating velocities. Anything that is intensive due to inefficiencies in Mojang or our own code will cause server tick lag. On Legion Servers, it is addressed as soon as it is noticed.