Did you just finish setting up a fresh CentOS7 installation and seem to be running into issues with yum update being extremely slow?
In this article, you'll find the simple fix for Centos7 yum update slow and what worked for me on resolving this very same problem.
I was attempting to install nano via 'yum install nano' and was experiencing extremely slow speeds. Running 'yum update' also resulted in extremely slow speeds even though the machine has plenty of download speeds available.
If you run into a similar issue, I recommend trying the below command to have yum use an alternative package mirror:
yum --disableplugin=fastestmirror update
Give it a minute or so and you should start to see the speed pick up way past the speed you saw when it attempted to use the fastestmirror.
Once the update command has run, you can try issuing an install command and you should see everything start to download pretty fast.