185MB should be able to saturate a 1Gb connection and you do have periods where you are almost saturating it. I'd say you should be able to get about 80MB/sec constantly. On my system I am getting from 105 to 125MB/sec reading and writing a 4GB mkv video file and I don't see why you can't get that either. Now 60MB/sec isn't bad either but it makes me feel like you have a much slower CPU than you have stated if this is all you can get out of it.
My suggestions are:
1) A direct Ethernet connection between the NAS and PC. Tell us the results of that.
2) Upgrade to FreeNAS 9.2.1.6 as the CIFS default setup is better (correct).
3) Replace the Ethernet cable.
4) If running through a router, is QOS turned on? I have a switch that has QOS that I can't turn off and is dependent on which port you use. This is why I recommend a direct connection.
5) Are you sure your PC can maintain a high throughput for the duration with some other device? It could be the issue.
6) Have you done a CPU stress test and validated the CPU model and speed? It's possible you bought a counterfeit part. It's a big thing now days. At least I hope that isn't the case.
Also, the jails should have no impact on your throughput, none at all unless you have some intensive task running and sucking up all the CPU cycles.
Code:
[root@ServerA /mnt/MS0/SERVERFILES0]# dd if=/dev/zero of=tmp.dat bs=2048k count=15k
15360+0 records in
15360+0 records out
32212254720 bytes transferred in 160.770165 secs (200362143 bytes/sec)
[root@ServerA /mnt/MS0/SERVERFILES0]#
I turned off atime in the pool and the internal speed increased to over 200MB/s.
The dd test on my computer only yielded 108MB/s for the large file transfer to the 2.5" HD's. If that is a true average, caching, buffering and transfer synchronization could explain the seemingly erratic transfer rates. I don't have another computer that I can stress the ethernet connection with. I'll try dd over the net from /dev/zero to FreeNAS. That should circumvent my computer's hard drive.
I too have seen bursts of over 100MB/s on my network. I don't see anything about QOS options in the setup of my router.
The info I have on the CPU comes from the BIOS setup page. It shows all the right stuff, at least as reported to the BIOS setup. How do you validate the model and speed? What stress test do you have in mind?
The performance quirks I'm seeing (variation in speed) are similar to that exhibited by my previous Intel-based FreeNAS build. The system elements that are common between the setups are the RAIDZ1 drives, and my desk computer. Different routers have been used in the past with the same variability. Now, new motherboard, AMD vs. Intel CPU, 8GB vs. 4GB RAM.
I'll have to round up some CAT5 cables to do the direct connect test.
Is the GUI update to 9.2.1.6 okay?
Thanks for the suggestions. It may take me a day or so to get these tests accomplished.