I ran into this a couple of weeks ago. I think that something was
broken
in the repos for a short period.
Also I ;)
In order to avoid the uninstall of a lot of packages due to
dependencies, and to proceed on 20 machines, I preferred to use a less
elegant way (use it at your own risk - be careful some one line commands
are split on multiple lines in this message and you may have to adapt
the name of the packages to yours):
rpm -e --nodeps xorg-x11-drv-nvidia-340xx.x86_64 \
xorg-x11-drv-nvidia-340xx-libs.i686 \
xorg-x11-drv-nvidia-340xx-libs.x86_64
yum -y install xorg-x11-drv-nvidia-libs.i686 \
xorg-x11-drv-nvidia-libs.x86_64 xorg-x11-drv-nvidia.x86_64
akmods --force
rpm -e kmod-nvidia-340xx-3.17.8-200.fc20.x86_64-340.65-3.fc20.1.x86_64
akmods --kernel 3.17.8-200.fc20.x86_64
then to be sure:
yum -y upgrade
and
reboot
Hope this will help.
Cordially,
--
NVieville