so how many cores do I need on the server?

[carboncow]

I've been using Fusion for years but I've never really know how cores are handled. If I'm not doing anything on the guest system that requires multi-cores then obviously one core assigned to guest OS is fine. So does a i5 system (two cores) have one core going to the server and one to the guest?

If I want to run two guest OS running databases and simple processes am I good to still use a 2 core server or should I be getting and i7 so everyone can have their own core from the quad core server?

I've been running Fusion for about a year in a product environment with Server 2008 running vendor specific software against the wishes of the vendor. Never had to reboot the guest once in 4 months of operation...runs perfect so screw them! So now I want to run two guests and am wondering how the two core (i5) mac mini I have will do with this (16gb of RAM).

[weinstein5]

Welcome to the Community - remember Fusion is nothing more than application running on top of OSX - so it is the operating system that schedules Fusion - all Fusion can do is request processor time on a specific CPU from the OS - so the OS will use all cores - each VM vCPU can only run on a single at a time - that is a simple explanation on how CPU scheduling works -

Now on to your question if the load is not high from the VMs than yes you should be able to run two vms concurrently.

[ColoradoMarmot]

For OSX guests, always used at least 2 cores.  Otherwise, each VM needs to have at most N-1 (where N is the cores in the host server).  I can run 4-5 1-2 core VM's on my 4-Core host without an issue.