Looking for some very small wall-mountable options for a 4 channel 3CX system advice. The hardware specs start at 16 channels and an i3. Not sure what is actually needed to run a 4 channel PBX. I've used a lot of the APU2C4 boards for freepbx systems and they work great. They are quad 1Ghz though. The UP boards are pretty similar but with Atom CPUs (until the more expensive units). Are these acceptable CPU wise? Or do I need to get into an i3? And if so, any suggestions on a low-cost, wall mountable option?