Best upgrades for a late 2012 Mac mini Server?

[docprego]

It's not that I am unhappy with my Mac mini, on the contrary I love it. But with El Capitan around the corner I am starting to think about taking it to the next level of performance.

My current configuration:

2.3 GHz i7
16GB 1600 MHz DDR3
Intel HD Graphics 4000 1024 MB
1.12 TB Fusion Drive consisting of a 120GB Mushkin Chronos SATA SSD and one of the two hard drives that came with the mini.

The SSD is probably the weak link in this chain as I bought it in 2012. I'm not well versed in SSDs so I'm not sure if upgrading it will be beneficial. It's specs are the following;

Max sequential read: up to 550MB/s
Max sequential write: up to 515MB/s

Any ideas or suggestions to turbocharge this mini are appreciated.

 

[wlossw]

You will be limited by the speed of the Sata connection. The only thing that might speed up your setup is a larger ssd, and even that is questionable. As configured your Mac mini is about as fast as it is going to get.
P.s. You could replace both drives with ssds and configure raid 0, thus doubling drive speed.