Server PPPOE X86 PC

Guys, we have 3 CCR 1036 to concetrador PPPOE server . I’m disabling a server cache with the following configuration :

Intel Xeon 3.5GHz 15MB Cache six core
Ddr3 1866MHz 32GB
1 x 240GB SSD
4 x SAS 6Gb / s 3TB raid 10 hardware controller pci off board 1GB / s
4x gigabit intel



I am thinking about riding it like a server pppoe , worth it? What is the experience of you with OS router with this type of service ? It will be only server pppoe with OSPF together.

How many users can put this server averaging Internet 12MB for each user ?