My 2014 2.8ghz/8gb Mini media server had an issue last week. Before getting it, I used a base 2014 1.4ghz/4gb Mini which was painfully slow with the 5400RPM internal hard disk. So, I cloned the internal SSD from the bad mini to an old Samsung T3 SSD as a boot drive for the 1.4ghz/4gb Mini and swapped it. Am quite surprised, can't tell any difference using iTunes (Mojave) with home sharing plus directly streaming Sling and Sirius XM.
Only half the CPU speed, half the RAM, external SSD about half as fast and HD 5000 graphics vs Iris. All goes to show, you don't need much of a computer for this kind of thing.