Differences between standard and rescue kernels

[Bruno Wolff III]

On Sun, May 17, 2015 at 23:31:56 -0400,
  Alex Regan <mysqlstudent at gmail.com> wrote:
>Hi,
>
>I installed fedora21 on an AMD x86_64 box then moved it to an Intel 
>x86_64 box and it would no longer boot. It would get to the following:
>
>Switched to clocksource tsc
>
>then just sit there. Booting from the rescue kernel worked properly.
>
>What is the difference between the standard default kernel and the 
>rescue kernel?

When dracut is used to build the initramfs it includes more modules than 
when it is built for a specific host.