Insomnia thoughts:
Could one create a raid Z1 array with Optane drives without dramatically increasing latency?
From what I remember, a hardware based raid would add a fairly noticeable amount of access latency and as much as I believe ZFS would resolve that, I would prefer to ask people much smarter than myself before making any irresponsible decisions.
That sounds cool, you should build one and see if it meets your requirements.
Remember a ZFS server uses a large RAM cache which with async writes should make it all the same latency, SATA SSD, HDD, NVMe SSD or OPTANE should all be the same, as long as the cache never gets too full.
In terms of the fastest ZFS array do it with two mirrored VDEVs rather than RAIDz1.
That’s 4 drives arranged as mirror + mirror.