yum very slow (not downloading but installing)

[webix]

Hello folks.

Can someone explain me why yum is extremely slow installing packages?
I have a i3 @ 3.8Ghz, 32Gb RAM and 2 disks installed on a RAID 1 by hardware.

When i run yum to install a package, he takes really long time. Not downloading the package (that takes just a few seconds), but installing it.
For example, it take almost 6 minutes (5:52) to install the mlocate package.
On another system, with the exact same hardware, it take 18 seconds to install the same package.

Regards