[CentOS] CentOS 7 on HP DL160 G6

I am running the latest updated version of CentOS on a HP DL160 G6 server as a workstation with the Mate desktop, not Gnome. The only expansion card I have installed is a MSI Geforce GT710 graphics card driving two monitors.

Unfortunately the computer locks up at random intervals: neither the mouse nor the keyboard work and I lose the SSH connection to the computer I have used to see if the entire computer locks up or only the desktop. If I leave the computer in this state it eventually reboots.

Any suggestions on where to begin researching this?

Thank you.