Network speed is very slow in Win11 VM

[ErikT5]

Hey all,

I'm looking for some suggestions to improve my network/Internet speed. For testing, I just did a simple test using speedtest.net to gauge my Internet speed. In my host OS, my network speed is about 2.3Gbps down and 350Mbps up. In my fresh Win11 VM, I am getting about 300Mbps down and 320Mbps up.

I am currently running Parallels 20.0.1 (55659). I have tested this with both Win11 Pro x64 and Win11 Enterprise x64. Both have pretty similar numbers.

Here's what I have tried:

• In Win11, set Offload Tx LSO to disabled for the Parallel's virtual NIC
• Set Parallels config Optimization to No Limit
• In Parallels config, I tried every setting for Network including Network Conditioner-Custom-unlimited/unlimited. The fastest option from my testing appear to be Default Adapter
• In the Win11 VM, set the Services-QoS-Throttle rate to 0. I know this isn't really tied to overall performance but is an option I tried.

Are there other options I can try? I know there will be some overhead when traversing VMs but this discrepancy is well outside of what I was expecting.

 

[ArielC1]

Good evening! I was downloading a game from EA and it was downloading at a speed of 300KB/s. After turning on "Network Conditioner" in the virtual machine settings under Network, I dropped to a download speed of 13-15MB/s. Apparently, it's set by default to a limit so it doesn't affect the network or for some other reason.

 

[KevinS25]

Thought I'd just update on my problem, although I never found a fix. However I bought a new Apple silicon Mac mini, and
did a complete new install of both Parallels and Win 11, just copying back in needed files.
My problem no longer exists and I have the full download/upload speeds in Win 11.

 

[Flight1]

I had the same problem and ended up reinstalling Windows. Everything seemed fine until I finally wanted to start downloading Visual Studio. At that moment, I found out that the situation was repeating itself. The download speed dropped to hundreds of kilobits instead of hundreds of megabits... But at that moment I remembered what I did last in Parallels settings for the virtual machine. I set the optimization to medium! So i reverted the setting to "no optimization" and there it is, internet speed is back to normal.

THANKS!! its really helpful for me!!

 

[DanC15]

After a long time, with no issues using Windows 11, I did a little reconfiguration and ended up with the dismal network speed numbers reported here. I finally remembered checking "Mirror Mac and Windows user folders". Unchecking that fixed everything (for now). Maybe this will help others.

I'm a longtime Parallels user and have used the mapped user folders feature quite a bit with no problems, but that no longer seems to be possible. I'm using PD 26.5 on an Intel Mac and won't be getting any updates.

Truthfully, the reasons for not using this feature are even stronger now in this new age of AI-assisted attacks and hacks, so I'm happy to leave it disabled.