Slow write speed to cache & unassigned m.2 drive

[BCM]

I've been searching the forums and troubleshooting this for a few days now. I have extremely slow write speeds over the network to my ssd cache as well as a unassigned m.2 drive on my unraid machine.

 

I've tested network speed to the server from my main computer (that I'm trying to write from) with iperf:

-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.1.51, port 53817
[  5] local 192.168.1.50 port 5201 connected to 192.168.1.51 port 53818
[ ID] Interval           Transfer     Bandwidth
[  5]   0.00-1.00   sec   103 MBytes   860 Mbits/sec
[  5]   1.00-2.00   sec   112 MBytes   941 Mbits/sec
[  5]   2.00-3.00   sec   112 MBytes   941 Mbits/sec
[  5]   3.00-4.00   sec   112 MBytes   941 Mbits/sec
[  5]   4.00-5.00   sec   112 MBytes   941 Mbits/sec
[  5]   5.00-6.00   sec   112 MBytes   941 Mbits/sec
[  5]   6.00-7.00   sec   112 MBytes   941 Mbits/sec
[  5]   7.00-8.00   sec   112 MBytes   941 Mbits/sec
[  5]   8.00-9.00   sec   112 MBytes   941 Mbits/sec
[  5]   9.00-10.00  sec   112 MBytes   941 Mbits/sec
[  5]  10.00-10.01  sec   806 KBytes   941 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  5]   0.00-10.01  sec  0.00 Bytes  0.00 bits/sec                  sender
[  5]   0.00-10.01  sec  1.09 GBytes   933 Mbits/sec                  receiver
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------

 

I've also tested write speed directly on the server to the m.2 drive:

 

dd if=/dev/zero of=/mnt/disks/Samsung_SSD_970_EVO_250GB_S465NX1KA61169W/test bs=32G count=20 oflag=dsync
dd: warning: partial read (2147479552 bytes); suggest iflag=fullblock
0+20 records in
0+20 records out
42949591040 bytes (43 GB, 40 GiB) copied, 119.243 s, 360 MB/s

 

My main computer I'm connecting to the unraid server with is a mac, I've tried connecting via SMB as well as AFP with no luck. All file writes I did testing via finder and writing a 7GB file to the m.2 drive as well as the cache separately.

 

Also tested by selecting the mounted share via the BlackMagic Disk Speed Test app.

 

All results in a write speed of around 20-25 MB/s.

 

Any help / ideas would be greatly appreciated!

 

server-diagnostics-20190219-1020.zip