[CentOS-devel] CentOS 7 gome system monitor CPU usage

>  loaded the Gnome desktop

I think I see part of your problem right there. The Gnome3 desktop is
amazing bloatware. If your RAM is not generously allocated for all the
debris on a typical Gnome desktop, you'll start swapping  as well as
sucking CPU for pointless 3D acceleration, especially in a VM.

You also didn't mention which virtualization technology you used. A VM
that supports paravirtualization, can be far more efficient than a VM
for which a server must do full virtualization.

> I'm astounded. I have no way of knowing if the problem is also present in RHEL 7. I can say it's not at all present in CentOS 6.5. I have a fair amount of experience with that OS.

Compare apples to apples. Try a much lighter window manager and see if
you have the same performance issue with something like XFCE. If you'd
like to be really retro, you can grab my vtwm building tools at
https://github.com/nkadel/vtwm-5.5.x-srpm and use something older,
more stable, and much lighterweight than any of those that compiles
from the same codebase on either basic OS.