10GbE Networking and Slow Transfer Speeds on 2018 Mac mini

[Aboo]

Hi,

I am trying to troubleshoot my network setup and hoping to get some advice on the problem. Here is my current setup:

Mac Mini 2018 with 10G ethernet port, connected to an external thunderbolt 3 SSD. Read/write speeds according to Blackmagic are about 1500 MB write and >2k MB read. The external drive has been shared through system preferences (i.e. file sharing through SMB).

The Mac Mini is acting as the "server" in my set up. My "client" is an iMac Pro. Both machines are connected to a Netgear GM110X switch with Cat7 cable. iperf3 indicates 9.91 Gb link between the two computers.

The problem is, when I used Blackmagic Speedtest to test the read/write speeds on either the Mac Mini external SSD or the internal SSD, the max speeds I get are around 700 write/750 read. This appears to be about half the actual 10Gb bandwidth. I have taken both computers off the switch and direct connected them as well, to ensure this was not a switch issue, and read/write speeds are exactly the same.

I have jumbo frames enabled on both computers by manually changing the MTU to 9000. The switch also supports jumbo frames automatically.

Any thoughts on what I am doing wrong here?

Thanks!

 

[dia3olik]

Yeah...SMB is the culprit imho

try with NFS which is much much faster and with less overhead

or eventually AFP and report back ;-)

curious of your results...it could also be a PCIe bottleneck???
It would be strange tho since 10GB theoretically should have its dedicated PCIe x4 link, no?

 

[northernmunky]

It 'could' be SMB packet signing, its been known to kill performance.
Try these instructions and try a speedtest again:
https://support.apple.com/en-gb/HT205926

 

[Aboo]

Yeah...SMB is the culprit imho

try with NFS which is much much faster and with less overhead

or eventually AFP and report back ;-)

curious of your results...it could also be a PCIe bottleneck???
It would be strange tho since 10GB theoretically should have its dedicated PCIe x4 link, no?

Thanks for suggestion - any idea how to share an external drive via NFS on Mojave? When I use the built in file sharing tools, I can only use AFP or SMB. It seems like previous versions of OS X Server Tools allowed you to set up NFS shares, but the most recent version has been stripped down significantly and does not have this capability any more.

I don't think its a PCIe bottleneck since like you say the 10GbE has its own PCIe x4 link.
[doublepost=1547958604][/doublepost]

It 'could' be SMB packet signing, its been known to kill performance.
Try these instructions and try a speedtest again:
https://support.apple.com/en-gb/HT205926

I forgot to mention this in my original post, but I did turn off packet signing. Prior to doing that my read/write performance was in the 400-500 range.

One would think you should be able to reach the theoretical maximum even if testing to the internal SSD of the Mac mini, but I am getting essentially the exact same results when testing to either the external thunderbolt 3 ssd or the internal Mac mini ssd from an iMac Pro client.

 

[treekram]

I use the raw bit/sec rate and divide by 10 rather than 8 (bits per byte) to get a realistic maximum throughput on a network without any contention.

The graphical tools for managing NFS may no longer be there but it appears NFS is still there in Mojave. I have used it on a Mojave client to a Sierra server. A quick search on the net indicates that some people have problems using specific software packages which use NFS on Mojave but that appears to be peculiar to the software. If you're looking for a NFS manager, there's an app called "NFS Manager". I haven't used it but it came up in a search - I set up NFS using the Terminal app.
https://www.bresink.com/osx/NFSManager.html

If you need assurance that NFS works on Mojave (server) and/or instructions using the Terminal to get a basic setup going, let me know - I can try it out on Mojave (server) and I had written basic instructions a while back. Again, the client portion seems to work OK in Mojave.

 

[Dameatball]

It 'could' be SMB packet signing, its been known to kill performance.
Try these instructions and try a speedtest again:
https://support.apple.com/en-gb/HT205926

I recently Found the same article after I got fed Up of getting half the throughput using SMB VS afp. I turned off packet signing and directory caching and now SMB and afp are getting gig throughput (gig network).