Slow write speeds on TrueNAS Scale

[magifeda]

I just build a new TrueNAS Scale box using latest 22.12.3.1. I have a Dell T3620 with 32GB memory. I have 3 x 4TB drives connected to HBA LSI 9200 flashed in IT mode. My write speeds are below 20MB/s with windows box transferring files larger than 200MB up to 2GB files. Any help would be appreciated. I am trying also to run iperf3 tests, but get connection refused messages.

 

[magifeda]

Other things I can think of are are the drives are setup as a Raidz1. The hard drives are Hitachi HUS724040ALE640 7200rpm drives.