1. OS: CentOS5.7 2. Arch: x64 3. Java: Code: java version "1.6.0_20" OpenJDK Runtime Environment (IcedTea6 1.9.8) (rhel-18.104.22.168.8.el5_6-x86_64) OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode) 4. Wrapper: None 5. Bukkit: 965-1173 6. Command: Have Tried: java -Xms512M -Xmx1536M -jar craftbukkit.jar java-Xms512M -Xmx1536M -Xincgc -jar craftbukkit.jar java -Xms512M -Xmx1536M -XXermSize=128m -XX:MaxPermSize=256m -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSParallelRemarkEnabled -XXarallelGCThreads=1 -XX:MaxGCPauseMillis=50 -XX:+UseAdaptiveGCBoundary -XX:-UseGCOverheadLimit -XX:+UseBiasedLocking -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=15 -Xnoclassgc -XX:UseSSE=3 -XX:+UseFastAccessorMethods -XX:+UseStringCache -XX:+AggressiveOpts -jar craftbukkit.jar 7. Plugins: Code: mcbans : 3.0 WorldEdit : 4.6 BlockHat : 1.5 iConomy : 5.01 WorldGuard : 5.2.2 Redeemer : 1.0 ColoredSigns : 1.1 LogBlockQuestioner: 0.02 RetractableBridge : 1.3.7 MobDisguise : 1.62 PorteCoulissante : 1.2.2 Permissions : 3.1.5 CommandBook : 1.5.2-customized BorderGuard : 4.11 iChat : 2.3.3-p3 LogBlock : 1.26 LWC : 3.5 8. Wrapper: None 9. Tried: I have tried almost everything... No plugins, Vanilla, running on VirtualPC, running on Home PC, ... 10. Tried (in list): Everything in list (It happens in Bukkit and default minecraft. I know this is the Bukkit help section, but I have tried many places and hope that someone here can lead me to a fix.) I am experiencing very high CPU usage for Vanilla and Bukkit servers. I am getting around 60-100% CPU usage (1 core of a i7 3.0 Ghz)(Happens on virtualized Servers(Xen, VirtualBox)) with 4 people online. The CPU usage of the server when it is empty seems to be around 10%. And seems to increase by 10-15% per player that is online. I have tried almost everything. When I tested an exact copy of the server on my home PC the CPU usage seemed much lower. (for the core Bukkit is running on) I have tried it on my VPS and on a VirtualBox running on my home PC. When running the server on the VirtualBox the CPU usage seems very high. I know this isn't normal. I have heard of many people with this problem. I see many server with similar hardware hosting 30+ people. How would mine get this bad?