As alex_markey posted here: http://www.spigotmc.org/threads/packets-slowed-down-in-latest-builds-causing-lag.1926/ This is what the lag looks like, it wasn't happening to me on build #735, but it has been happening to me on the late 1.5.1 builds and on the latest 1.5.2 builds #834-#844. Here's a short video of the lag (ignore the start text): You can see how only animals and players lag but there is no block lag. Also that server had no plugins and the server specs are 64 GB DDR3 ECC, Intel Xeon E5-1650, 2x 120GB SSD and 1GB Uplink. When we switched up the jar to the #735 this lag stopped immediately. I'm not sure why you don't see this lag, but as you said in the top link thread: This lag is happening to people in america, united kingdom, australia, new zealand, asia, other european countries that do not speak english fluently, from what I've asked people in my server. So this cant be from internet speeds. It would be nice if you could just 1 release on 1.5.2 with the 10ms delay back to normal as in build #735 on 1.5.1 and if the lag does stop that would be greatly appreciated to have all builds on that ms delay. Thanks for reading this far. Kind regards, dolan.