I build a Truenas with 4 8Tb NVME (RAIDZ1 Vdev)
I enable SMB share
I did a BlackMagicDesign Speedtest from a Mac (10Gbe) ➧ 900 MB/s read & write : Good
I did a BlackMagicDesign Speedtest from a PC (10Gbe) ➧ 90 MB/s read & write : Slow
Any explanation ?
Truenas is 25.04 (256 GB RAM)
Switch Ubiquiti USW Entreprise XG24
I tried to solve the issue with AI without success!
AI tried to disable “server signing” in the smb config file.
May be I didn’t succeed.
Thanks in advance
You should provide hardware list for truenas, PC and perhaps even for Mac.
can you use iperf3 instead to test speeds?
Run iperf server on TrueNAS and connect from windows and do multiple threads (-P * option)
This will tell you if the network is fine at least and then you can look at Windows / IO.
Thanks
Of course
Truenascale HW
Mobo : Supermicro X11SPM-F
CPU : Xeon 6234
RAM : 4x 64GB ECC
NVME : 4x SN850X 8TB
NIC : Melanox Connect MCX4121A-ACAT
Switch
Ubiquité USW Entreprise XG24
Mac : 2x Mac mini M2 Pro with 10G NIC, MacOS Sequoia
PC : Windows 10, other spec are expected soon … (I’ll edit later)
You got the right drivers on that Mellanox card? Nvidia has updated drivers for it, they call them the OF2 driverset for those x4 cards. WinOF-2 / WinOF Drivers
Also I’m assuming you have it in an x8 slot. It needs the bandwidth.
Resident AI @winnielinnie may concur here. 
This is the server NIC… You cannot (or rather should not) update drivers in TrueNAS. And the NAS appears to behave as hoped from a Mac client, so the suspicion is on the Windows client.
Good catch, I assumed the Windows PC was using the Connectx4. Absolutely DO NOT touch the drivers on the server, the Mac client proves it’s going full speed already. But since the focus is still obviously on the PC client, what card is it using?
Update
Truenascale HW
Mobo : Supermicro X11SPM-F
CPU : Xeon 6234
RAM : 4x 64GB ECC
NVME : 4x SN850X 8TB
NIC : Melanox Connect MCX4121A-ACAT
Switch
Ubiquité USW Entreprise XG24
Mac : 2x Mac mini M2 Pro with 10G NIC, MacOS Sequoia
PC1 :
-NIC Asus XG-C100C 10go PCI-E Network adapter
-Processor : Intel(R) Core™ i7-6700K CPU @ 4.00GHz
-GPU: NVIDIA GeForce GTX 1080 Ti
PC2
Switch And Truenas are connected via 2 SFP28 DAC
MACs & PCs Are connected to the Switch via CAT6 cables
So PC1 is the bad result. Looks like that little Asus card has an Aquantia chipset, nothing too weird there. Is it showing a 10G link in Windows? Can you iperf it to something external and get good speeds?
I just want to feel comfortable that it is capable of much more speed than Truenas is giving it by testing something else.
good question !! I’ll test with Synology NAS and report
Okay BlackMagicDesign Speed test From the PC on the Synology (10Gb/s NIC) ➧ 400 MB/s read & write : Average Good
And yes 10G NIC win the PC works as expected Speed (10Gb/s)
Gonna be a tough one I guess. For fun, install an app for me on Truenas. It’s called Open Speed Test. All it tests is how fast you can move data between your client and the server so this is actually helpful. If that is also stunted, and we’re pretty sure the physical layer is ok now, next step is looking closely at smb. But let’s see how much data you can move between PC1 and Open Speed Test.
AI advice is to disable the SMB parameter “server signing” on Truenas. I tried, … but I think I didn’t really succeed.
I’m no expert with command line and half AI “suggested” command lines returns errors (generating isn’t always good :-)).
if someone knows how to properly and simply disable SMB parameter “server signing” … it will be much appreciated
Thanks
AI is know to return garbage and/or dangerous, destructive, commands 
Do not run AI-suggested commands you do not undertsand (of course, if you understood, you would not have used AI in the first place).
I suppose you would never be tempted to “remove the French language pack” but still…
I agree with you.
I’ll keep searching a solution without AI
Let’s go back to my Open Speed Test chief, chatgpt didn’t tell me to say that.
Okay I found The issue.
I had a loop in the network.
Truenas was plugged to the switch with 2x25Gbps (aggregated) & 1Gbps
The 1 Gb Cable is for BMC NIC … but was plugged in regular 1Gbps Mobo’s NIC
As soon I plug the 1GB cable in the BMC NIC, reading and writing speed are as good as expected from Windows 10 and 11 PCs
My bad
I wish to learn from my mistake. (I need you on this)
my guess is that SMB multichannel was enable and did a terrible job
Have you any other explanations ?
macOS seems to not do anything with Multichannel by default …
Thanks
There’s a check box for smb multi (off by default) in the advanced options, I think. That required effort, unless it came along for the ride when you bonded 2 interfaces.
Maybe something told you to enable it to get full speed out of smb. But I was right about one thing, it was a tough one,because nobody knew there was a loop.
Well, actually it is not a loop.
Multichannel needs 2 NICs on the client. And IIRC, it needs to be enabled on the client as well (at least it was necessary in the past).
We can troubleshoot further if you want to. Are ip addresses on your truenas static or obtained via DHCP?
Now you’ve got me curious since I thought this thread was finished. What would cripple PC performance, but not the Mac, the way he had it setup before?
