Slow 10 GBe connection in Windows 10 VM


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Hi guys.

 

I have a 10 GbE network card in my unraid server. Its the supermicro C9X299-PG300F motherboard with the Aquantia AQC107 10G network chip onboard. On the server I have a Windows 10 VM with two nvme drives and a gfx card passed through to it. When I try to connect to my qnap with the windows VM and copy a file I get a little bit over 1 Gb (150 MB/sec or so) connection. This is also confirmed with iperf3 that shows 1.76 Gbits/sec towards the qnap.

 

But when I run iperf from outside of the VM, straight on the unraid server against my qnap, I get the full 9.5 Gbits/sec.

 

How do I get the VM to use the full connection speed?

 

The virtio drivers are installed, and it shows up as a redhat virtio network adapter, with a connection speed of 10 Gbit/sec

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  • 1 year later...

Any luck on this? I am having *very* similar issues. My iperf results from my macbook w/ 10gbe adapter is over 8Gb/s while from a Windows 10 vm doing an iperf test I'm getting results of 1.19 Gb/s. This is driving me crazy! :) I've been searching for over a day and I'm struggling, so any help would be appreciated! virtio drivers are installed on the VM. 

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Hi @jonp! Sorry for the slow reply! It was my first post so I wasn't sure when it'd get approved.

My connection from my Macbook is using a thunderbolt 3 adapter from CableMatters. I attached a quick diagram showing the setup. My main issue is I'm confused why the gust connection to the host is so slow... significantly slower than the connection from my MBP to Unraid Server.

I'm using the asus xg-c100c on the Unraid server and in the vm, I just set it up using the virtio-net driver. Also of note is I'm running Version: 6.9.0-beta29 of Unraid. 

network.png

Edited by mattalachia
added model of network card + unraid version
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Hi again Matt,

 

No worries on the delayed reply!  This definitely explains a bit more for me.  I've tried recreating this issue in our lab setup, but I don't have the same ASUS NIC as you.  So to confirm, a direct transfer from Mac to server is attaining pretty high speed, but when the VM is the source instead of the Mac, you see the speeds drop.  Is that correct?  Beyond iperf, have you tested just copying files over?  I'm assuming you're copying them to a share located on SSD(s).

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Yeah, so I'm getting proportions similar to iperf when transferring files to shares. Also similar results on Blackmagic Disk Speed Test (primary use for one of my VMs will be video editing once this gets worked out!). I'm writing to a share that is only stored on cache on these tests. I'm pretty sure before I updated to the beta I was getting good speeds. I attached a photo I took to show my buddy how nuts this setup is with a pcie 4.0 nvme drive.

I've made new VMs from scratch as well and still getting similar results.

Resolve.jpg

Blackmagic_Design_Disk_Speed_Test.jpg

62327491530__D4D39C27-45E9-4A72-A520-E4C2C80EBD41.jpeg

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I set up a Ubuntu VM pretty quick and getting similar results. I could try reinstalling unraid back to the stable version to verify that everything was fast af. I was just having some issues with creating VMs with my hardware setup and the upgrade seemed to make things much smoother.
QEMU__Ubuntu__-_noVNC.jpg.27018446f30705107a43202c3619a040.jpg
is there a way to verify on your micro tick router that traffic between the VM and the host is not actually traversing the physical network? A 10 gig interface isn't even required to do what you're trying to do.

Sent from my Pixel 3 XL using Tapatalk

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Yeah, I dont think it has anything to do with the 10gbe interface. I'm pretty new to virtualization and was banging my head on why the guest/host speeds are so slow and ended up traversing irrelevant things out of desparation! :)

 

As far as the mikrotik, nothing is hitting the switch which is expected when looking at the data during transfers. 

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@jonp I can make a new thread if that is helpful, but I downgraded back to unraid 6.8.3 and results are confirmed to be what I expected. I did nothing else other than rollback via the GUI, then go to VMs and and I reselected a Q35 machine and boom, everything was fast again. (web vnc messed up but no big deal at the moment)

image.png

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  • 8 months later...
On 10/22/2020 at 12:16 PM, mattalachia said:

@jonp I can make a new thread if that is helpful, but I downgraded back to unraid 6.8.3 and results are confirmed to be what I expected. I did nothing else other than rollback via the GUI, then go to VMs and and I reselected a Q35 machine and boom, everything was fast again. (web vnc messed up but no big deal at the moment)

 

 

hi there, could you specify exactly which Q35 machine version you used.

 

thanks

 

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