Hi @Alejandro_Garcia1 ---- Thank you for the report and my apologies for the troubles. In order to accurately evaluate this issue, I’d like to gather some information from you in regard what you are working with and how it is being used.
I see you have already started explaining your setup a bit. Core being ran on 2010 Mac Pro (OSX 10.10 w/ 32gb ram) and your music collection is being accessed via and external HD mounted to the Mac 
May I kindly ask you to elaborate further on your current setup, as seen here. The more detailed you can be, the better. I want to get an exact understanding of the gear you are using ( make / model), how it’s being communicated with (USB, Wifi, Ethernet), and what your network configuration is like.
Furthermore, can you expand a bit on when the issue started. Has it always been like this OR was this something that just started happening? If that is the case, were there any changes made to your setup? New gear? New applications being ran in the background? Driver updates?
Thanks!
-Eric