Solved Server memory problem

[wow996]

Im using mac OS X Mountain Lion
its my desktop computer but I have run a private server on it before perfectly
Im using Direwolf20 1.5
I didn't add any extra mods to my server
I run it with java -Xms512M -Xmx2G -XXermSize=128m -jar ftbserver.jar
So its kinda a weird problem even though I run my server with 2gb it acts like Im running it with 300mb so its lagging all the time. On the server gui it says it only has 22% free memory most the time. Anyone know whats wrong because this is pretty weird.

 

[cjm721]

It will only use as much as it needs.

 

[wow996]

I know that but thats not the problem if it was only using as much as it needed then I wouldn't be getting lag. But anyway I sorta solved the problem because I switched from using the vanilla-ish server to MCPC+ and that seemed to solve my problem.

 

[cjm721]

CPU could be the limiting factor. MCPC has alot of performance via calculations and threading improvements over default.