Parallel copy not improving file speed

[GameOver]

i'd setup a sync with 6 file operations either way, and it's still only copying 1 file at a time. It's indicating it's using 6 threads which to me would say it's using 6 CPU threads as in software like CopyMaestro but that's not the case either. CPU useage is minimal.

So my question is what is going on. This in theory should speed up file transfers to max bandwidth should it not?

I have 2 systems, with Raid 0 on both, a 10Gbe network card between them. one on PCIe3x8 the on PCIe4x8
the PCIE3 system is running 5x6TB Iron Wolf NAS drives with a max read/write of around 200Mb/s in single performance. the other system has 4x8TB Iron Wolfs NAS which are about 50Mb/s faster. Regardless speeds in FFS between the two are maxing out at 300Mb/s.

[xCSxXenon]

You misunderstand what parallel threads does in FFS. There is most definitely a bottleneck in your chain, probably the nature of mechanical storage and file operation overhead
https://freefilesync.org/manual.php?topic=performance