Even an old 3.5" HDD on its own is at least one order of magnitude (10x) faster than needed (IOPs or MB/Sec) for streaming hi-res music. Music playback data is primarily sequential, not random I/O so....
Very old 3.5" SATA HDDs are capable of at least 100 MB/Sec while a 2-ch 24/192 hi-res stream requires less than 10 MB/Sec. So that old HDD is at least one order of magnitude (10x) faster than needed. Many modern 3.5" HDD will be 2 to 3 orders of magnitude faster than needed.
The end result when playing music from NAS makes no difference whether you have SSD or HDD in the NAS. A SSD capable of hundreds of MB/Sec or thousands of IOPs won't do any better than an old HDD in a NAS playing music. Remember, we only need 10 MB/Sec for hi-res 2-ch 24/192.
And we haven't even mentioned the NAS 1-Gigabit/Sec network bottleneck that chokes the performance of your SSDs down to no more than 125 MB/Sec theoretical max over the network.
Did you actually noticeable a performance gain streaming from NAS when you switched from HDDs to SSDs? Maybe you did but like anything in audio the hard FACTS rarely matter ;-)
