Using #1240 64 bit java & and computer arch. I'm lagging in my own server, but my players say they don't experiance any lag! :O I see messages in console with a literally 20 second delay till i reach them in client. Whats happening :O
Although there are some issues like Donny says, I run my own server and play on it using the same computer and experience zero lag. I also have a very good computer and internet connection. These are my specs: Intel(R) Core(TM) i7 CPU 930 @ 2.80 GHz (8 CPUs) 4096 mb ram Windows 7 ultimate 32bit 100 mbps download speed and 5 mbps upload speed You don't need to get nearly this good to run minecraft on the hosting computer but having ram dedicated to minecraft and a powerful processor does help. Download and upload speeds help you and your players connect quite well too.
If you have a bigger world (over 100 mb) chunks just take longer to load when you first join or teleport to a region. If I remember, I'll edit this with more as I figure them out.
When playing on the same machine that you're running the server on, make sure to connect to 127.0.0.1 or the machine's LAN address instead of the external IPv4 address. With some routers using your own public IPv4 address generates strange results like this "local lag".
Hmm, Also another weird lag thing. My friends living like halfway across the world do not lag, but my neighbours do! Weird huh? Any ideas?
I have lag problem in 1240 Sometimes random player freezes for about 5 minutes Sometimes when player is connected he is already frozen, in this case delete world/players/playername.dat resolve problem.