our cluster runs till 2014 on supermicro board.
It is not unusual that still mainboards with mga graphics cards are delivered.
So I have then adjusted the mga driver from CentOS 6 – the specification file – , to be build on CentOS 7. Since then this runs on the headnode without failures.
Maybe you should provide this via epel. The source can be found here:
This is the latest from CentOS 6.9.