Linux Dedicated Server - Multicore Support

[AlphaAlpacca]

Hy together,

we run a new 7DTD Server on my Cluster (http://7daystodie-servers.com/server/29298/ *spam* ). We have already a pretty good performance, because I dedicated pretty much ressources to it but I´m wondering, why its not using all of it. Currently its not going to use over 4-5GB Ram and using only one core (The OS is using the second one but the others are 100% sleeping)

I guess there are some hidden configs or startup flags to make the server support more RAM and more than Multiple cores?

Anyone got some suggestions for me?

Thanks in advance!