Kitz Forum
Computer Software => Windows 10 => Topic started by: Alex Atkin UK on May 10, 2021, 05:47:50 PM
-
Anyone else ran into the issue of LAN speed throttling on Windows, especially uploads? All my Windows PCs recently are being limited and I have no idea which update caused it.
I just built a 5950X and finally can use my Aquantia 10Gbit card again, but checking with iperf3 its limiting to 8.9Gbit down from the NAS and 1-2Gbit up. It even drops as low at 800Mbit up sometimes. Parallel transfers don't help.
Boot into Linux and its 9.2 - 9.4Gbit both directions!
My old gaming PC using a USB 5Gbit card seems fine for downloads, hitting 3.6Gbit (USB overheads limit) down but 1.2Gbit up.
Then on my laptop in Linux I can hit 850Mbit peak pulling off WiFi from the NAS, but its limiting to 300Mbit in Windows.
I've looked into all the usual solutions on Google for speed issues and none of them make a blind bit of difference, other than I managed to speed up downloads a bit on the 10Gbit machine by turning off interrupt moderation.
At this point I'm just waiting on a Windows Update to magically fix it, as happened before when I got my gaming laptop a few years ago and it had the same problems out of the box. But I just wish I could figure out WTF is going on!
Obviously this has zero impact on Internet speeds as network speeds are well above that, but its extremely frustrating for NAS access.
-
No idea as I dont use/need those kind of speeds.
But you at enterprise grade speeds there and its those sort of speeds where much of the offloading features are designed for as well as jumbo frames.
So run ethtool on linux, to check what is enabled on the NIC, also check MTU sizes.
In addition linux has its own software based segmentation offload that is on by default even for cheapo consumer cards, it likely has that as a benefit over windows.. This will be visible in ethtool as well.
-
Bear in mind I used the same card several months ago in Windows and it was perfectly fine, this is a recent change to ALL my Windows installations as you see its even impacting WiFi just differently.
Jumbo frames are really not necessary, I did extensive testing back then and it just brings its own can of worms for very little benefit.
-
Yeah I advised to check not necessarily change anything, just to observe the difference in software configuration.
But if you really feel that's a waste of time then try downgrading the drivers in windows, they may have got updated via windows update.
-
Interestingly, it seems this WAS a conflict between the NIC in the Linux server and Windows.
I upgraded another PC to 5Gbit using the same card as my Windows box having problems, ran Fedora 34 on it and speeds were perfect between the two. So I went back and tweaked the Intel NIC in the server with:
ETHTOOL_OPTS="-K ${DEVICE} ntuple on; -C ${DEVICE} rx-usecs=0"
Seems to have solved the problem on that machine, but still having issues with speed on my laptops to the server being 1/3 of what they should be on WiFi and 2/3 on wired.
Windows on my gaming laptop to my Windows desktop over a 5Gbit USB adapter is really messed up though (480Mbit to 2.2Gbit variable), so it seems the server tweak is only mitigating the problem, its definitely still a Windows issue.