mmm,
Well you don't use ZFS on macOS to get performance. Not having a go at the macOS devs, they are champions!
It's just that I'm not aware of too many code-optimisations focused around speed have occurred for macOS. (I could be wrong, so apologies if I'm mis-typing)
People tend to use ZFS filesystem on macOS because they care more about the integrity of their data than speed.
Remember that ZFS appeared on macOS when HFS was the default—a 40 year old codebase initially designed for floppy discs!
APFS isn't much better when it comes to data integrity because it too does not calculate checksums on datablocks. (it does for metadata datablocks only from memory)
Here's a fun exercise in frustration:
If you want to share data on a single machine via multiple OSes and have performance, I suspect running a TrueCORE VM to drive your ZFS pool via macOS or Windows would yield better performance.
Far more complex to do, but if it's integrity
and speed you're after.
If you hosted the VM file on a exFAT partition using VirtualBox and gave it raw access to the ZFS disks, you might even be able to run/use the same TrueCORE VM via macOS and Windows or any other OS you choose, as long as VirtualBox has been compiled for the native OS. This would be neat!
Kind've like having your own locally resident NAS hiding inside your machine. vSphere comes to mind also here, it used to run natively on Apple Intel too a while back but am not sure if it does now considering Apple tried to kill off PCIe slots (and failed).
Clearly the easier option would be to use another old clunker PC, but with a 10GB ethernet card installed into one of its slots running TrueCORE and access it directly from your Mac with whatever OS you're running on your Mac at that time. This is what I do here at home with 10GB ethernet and the speed is mental. Plenty fast enough for my home needs for years to come.
There's a guy called
Art of Server on
ebay who I've purchased from multiple times in the past for storage focused items. He can help you attain ex-enterprise hardware (i.e. speed!) that are guaranteed to work with ZFS/TrueCORE. Intel or Chelsio 10GB ethernet adapters work well. You could go the cheaper SFP (fibre) option too if you were only wiring up your MacPro and the NAS box directly to each other for speed purposes, and then use gigabit ethernet (copper) back into your 1GB copper switch for your remaining/other computer needs.
Maybe it's time again to virtualise ZFS with the latest versions of macOS, Ubuntu, FreeBSD, TrueCORE and Win10, with multiple virtual disks and test the performance of mirror, stripe, raidz1 and raidz2 to see how the macOS compares.
This was done some time back and is still on the
wiki performance page, although I suspect things have changed since then.
I do remember ZFS on Mac around version 1.2 or 1.3 was very quick. I can't exactly remember the version number but I definitely still remember installing it onto a x6 drive pool and the I/O on the disks were going bezerk compared to the previous versions.
I don't know what changed in the code base after and around then, but for me, the drop in speed was especially noticeable when using ≥ 5 physical disks that I chose to move off macOS/ZFS. There are recent
posts commenting on poor performance too by the looks.
Food for thought.