alt Hacker NewsA single SSD can (or at least NVMe can). You have to question whether or not you need it -- what are you doing that you would go line-speed a large portion of time that the time savings are worth it. Or it's just a toy, totally cool too.
4 7200 RPM HDDs in RAID 5 (like WD Red Pro) can saturate a 1Gbps link at ~110MBps over SMB 3. But that comes with the heat and potential reliability issues of spinning disks.
I have seen consumer SSDs, namely Samsung 8xx EVO drives have significant latency issues in a RAID config where saturating the drives caused 1+ second latency. This was on Windows Server 2019 using either a SAS controller or JBOD + Storage Spaces. Replacing the drives with used Intel drives resolved the issue.
My use is a bit into the cool-toy category. I like having VMs where the NAS has the VMs and the backups, and like having the server connect to the NAS to access the VMs.
Probably a silly arrangement but I like it.