Figuring out transfer bottlenet or issues

TrueNAS General
1

Just set up TrueNas core system and when i’m transferring files to the NAS the connection maxes out at ~85mb/s. After reading some other posts i feel like it should be faster.

Hardware:
The GUI dashboard is reporting “1000baseT” this was from a dell precision 3640 so not sure what exact NIC was, running 4 12tb Seagate Exos in RAID Z1 with default set. Boot drive is an NVMe and 8 GB RAM

and my other computer has Realtek 8111h gigabit controller.

Tests:
When i test via iperf it shows 700 Mbits/sec. which makes me think if i divided that by 8 it gets to the 85mb/s.
But when reading from the NAS to my windows machine it’s showing 110 mb/s
And when i had both systems as windows before it would reach ~200 mb/s no problem.
The whole difference between mebibytes and bits and megabits making things more complicated. But basically, how do i know if this is the max speed or what’s the bottleneck?

2

Can you please post your complete hardware setup, including the exact type of HDs.

How did you setup your pool?

Realtek chipsets are often the cause for sub-optimal performance. The same is true for SMR Drives on ZFS.

3

Updated with more details let me know what else you believe is pertinent;

4

1000Base T is ~ 1Gbit/s ~ 125MByte/s
With overhead 110Mbyte/s is about what to expect.

5

Ahh I see, i’m hitting ~85 MByte/s on transfers to the NAS so can I assume that’s mainly overhead when going to NTFS to ZFS, or perhaps something else going on?