10G nic throttled to 80MB/s for some reason

[SMcDougal]

I have a weird 10GB nic situation - no matter what I try windows 10 file transfers are stuck at around 80MB/s.

Here are the specs:

8600k
Asus z390 Aurus pro wifi
16GB RAM
ADATA SX8200PNP 1T NVME SSD
Asus XG-C100C 10 G Nic

The NAS on the network.

SYNOLOGY 1819+
with a 10G Mellanox ConnectX-2

Switches:

Netgear GS110EMX
Mikrotik CRS305-1G-4S+IN

I've tested different cables (I'm using Cat6a), I've routed different ways through the switches. I've changed motherboards from ROG strix z370g- gaming (that setup had the same problem) - I've tried different PCIe slots. This is what I can see at the moment: I've also swapped out the Nic with a x550 T1 (Same result)



The weird thing is that I've used both 10G Nics in another rig and they both work perfectly - over 500MB/s - same NAS, consistently between different routes through the switches. Same NIC properties etc. Only real difference - it's a 9900k with two NVME drives.(I thought this would take up the PCIe lanes but it seems fine.)

So I'm a little confused about why the other rig is throttling so hard. Here is the iperf3 info




I've tried everything I can. I'm a bit stumped - I can only assume the cpu is the only thing that's the only consistent element that could be a problem. Or is it the NVME using up the extra chipset PCIe lanes?

Hopefully someone on here has a few ideas about what's happening?

 

[acquacow]

Check these:
https://blogs.technet.microsoft.com/netgeeks/2018/05/21/a-word-about-autotuninglevel-tcp-receive-auto-tuning-level-explained/

Fix: Slow Internet After Windows 10 Creators Update

I had similar issues, one of those two fixed it.

-- Dave

 

[SMcDougal]

Thanks Dave

I'll let you know how it goes. BTW your second link turned into pop up hell - but I googled the same thing and I'll let you know whether it works or not.

 

[acquacow]

Interesting... I've got ublock in place, I clicked an scrolled through, and no popups here...

 

[SMcDougal]

No worries, just letting you know. Nothing worked - I'm beginning to believe it's cursed.

 

[Dreece]

Sounds like an RSS issue, or it could be everything from autotuning to some filter in the network driver stack.

Usually (if the install does the dog work like some nic brands), if you uninstall the drivers, make sure they're gone completely, reboot, reinstall using the nic setup package, it might just set everything right... this works with Chelsio cards for example.

 

[Dreece]

If the re-install doesnt do it, go through your nic config and simply disable everything (ie arp, coalescing, checksums, all offloads, large sends etc)... then try iperf and see what you get, if you get something interestingly better, then that begins to lay down something resembling a tunnel with a light at the end... hopefully.