Problem Mindcrack pack, High CPU ussage with 13+ players

[lisim]

Ok Server Background

We have the following server :
E3-1230-V2 Ivy Bridge Xeon 3.3GHz, 16GB RAM, 480GB SSD Primary Hdd, 1TB Sata Secondary Hdd

We are Running a Customer 3.7 Debain Kernal
We have the MC server Runnign under a useraccount that only has access to the Server and the SSD nothing else dose

Server is all running off SSD and has 14gig ram in its Heap but will not use that much

The second we get a 13th player or more Console gets spammed with cannot keep up msgs although player do not report anyissues id rather nip it in the but before it becomes a noticeable problem client side,

Any ideas?

 

[lisim]

Any one else experincing this?

 

[glasspelican]

you may want to try tweaking the jvm
look -> http://forum.feed-the-beast.com/threads/server-lag.2501/
my server lags with 3 people until I tried this
Hope it helps

Edit: I am working on a build nearly identical to yours, let me know how it turns out

 

[lisim]

This is our launch Command

#! /bin/sh
java -server -Xmx12G -XX:permSize=128m -XX:MaxPermSize=256m
-XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC
-XX:+UseNUMA -XX:+CMSParallelRemarkEnabled -XX:MaxGCPauseMillis=50
-XX:+UseAdaptiveGCBoundary -XX:-UseGCOverheadLimit -XX:+UseBiasedLocking
-XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90
-XX:MaxTenuringThreshold=15 -XX:UseSSE=3 -XX:+UseLargePages
-XX:+UseFastAccessorMethods -XX:+UseStringCache
-XX:+UseCompressedStrings -XX:+UseCompressedOops
-XX:+OptimizeStringConcat -XX:+AggressiveOpts -jar minecrack.jar nogui

 

[glasspelican]

The largest differences I see are I add

-XX:UseSSE=4
-XX:ParallelGCThreads=4
-XX:ReservedCodeCacheSize=1G
-XX:+UseLargePages
-XX:CMSFullGCsBeforeCompaction=1
-Xnoclassgc
-oss4M -ss4M

I do not use
MaxGCPause
useNUMA
GCOverheadlimit
BiasedLocking
any compressed strings
any survivor ratio

This server side only mod may give you some more information
http://www.minecraftforum.net/topic/1548779-146-ticks-per-second-v0411/

Potential related Info
ubuntu x64 12.04 pre-release channel
i5 460m
8G ddr3 1333
java -version

java version "1.7.0_09"
OpenJDK Runtime Environment (IcedTea7 2.3.3) (7u9-2.3.3-0ubuntu1~12.04.1)
OpenJDK 64-Bit Server VM (build 23.2-b09, mixed mode)

If any other readers are wondering what this options do, this page has a description for most of the arguments we are using
http://www.oracle.com/technetwork/java/faq-140837.html

 

[lisim]

Ill try thoese changes, Is sse 4 on the new xeons?

 

[glasspelican]

the new xeon added sse4.2
sse4 has been included for some time
my server is using a first gen i5

If that dos not help, I’m out of ideas

 

[lisim]

how is this

#! /bin/sh 
java -server -Xmx14G -XX:PermSize=128m -XX:MaxPermSize=256m  
-XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC  
-XX:+CMSParallelRemarkEnabled -XX:MaxGCPauseMillis=50  
-XX:+UseAdaptiveGCBoundary -XX:ParallelGCThreads=4  
-XX:MaxTenuringThreshold=15 -XX:UseSSE=4 -XX:+UseLargePages  
-XX:+UseFastAccessorMethods -XX:+UseStringCache  
-XX:ReservedCodeCacheSize=1G -XX:+UseCompressedOops  
-XX:CMSFullGCsBeforeCompaction=1 -XX:+OptimizeStringConcat -Xnoclassgc  
-oss4M -ss4M -XX:+AggressiveOpts -jar minecrack.jar nogui

 

[lisim]

its running now but we do not have 13+ members on atm so its hard to tell how it is going