as pointed by John check Red Hat website for list of supported hardware against rhel 7.
You are in uk so you can have a check at mini-itx.com to choose a mobo.
I get the power consumption. But check the cost of the mobo and extra hardware and shipping vs the cost of power.
Is it a one year difference or ten years?
you might have a try to elrepo updated drivers kmod ir even their kernel for some unsupported hardware like ethernet adapter.
In my experience asrock is poorly supported by RH because of their choice in integrating some hardware. I had more chance with what is on jetway, asus or intel boards.
I'm just running a test install on the ASRock A330GC board and the network card appears to be detected fine. I was thinking it was quite slow to install, but then I remembered the Intel D946GCLF board has an SSD and the A330GC is running on a 5400rpm 2.5" drive.
Just for reference, SME 10 running on the single core Atom 230 1.6GHz feels fine now the SSL certificate has been generated. Everything is quicker than it used to be under 9.2, presumably because it now runs from SSD instead of 5400rpm 2.5" hard drive, even running spam-assassin scripts feel much more responsive than before.
I've revived many elderly Windows laptops by upgrading them to SSD and this also seems to have paid dividends on my mail server too!
Thanks to everyone for their input.
Jason.