Windows 10: Internet speed capped to lower than 150mbps in Windows 10 Pro, over 1000BASE-T link 600mbps...

Hello, I’m a Windows 10 user having a very very annoying issue. I'll put you in context.



I have a Windows 10 Pro desktop connected to a router with a 1000BASE-T over UTP Cat. 5e ethernet cable. My ISP provides 600mbps internet access.

A few months ago, I noted that my internet speed was slowing quite a lot, during a download that usually took most of my available bandwidth ~70MB/s, now was going less than 1MB/s. So, I made a speed test using my ISP's test. It showed around 2.5mbps.



As you would expect I cursed and sweared, initially I thought it was the ISP's fault, but I made another test on a laptop over 5GHz WiFi, that showed 400mbps. I thought "How is this possible over 1000BASE-T in my PC?". So, I rechecked my connection, Windows reported a 1000gbps link, I changed cables, even trying a Cat. 7 FTP, trying different NICs and adapters, but no change. I finally rebooted, and then I got 150mbps in the same test. So, I thought, "Is it fixed? Is not great but I got things to do", but with Windows 10, nothing is fixed



Note that I usually just put the computer to sleep, not shutting it down completely. So, the next day the test was 60mbps, and the next day again below 2mbps. I can't live like this, I was breaking my head trying different things, searching forums, and now I'm pretty sure this is a Windows issue.



I finally found that changing a setting via cmd, made a difference. This was the "Receive Window Auto-Tuning Level" feature. It was set using the netsh command. Firstly, I displayed its original value, "normal", I changed it to "disabled" and rebooted. Nothing changed as any other thing I tried. Then I changed it back to "normal", and then I rebooted again and then the test reported 620mbps! Is it fixed now? No. The next day it was going down again, 400mbps, okay that doesn’t have to be related, right? The next day, 150mbps, okay this is definitely going down again. Next day 60mbps... you get the point.



I investigated this issue furthermore, discovering what Receive Window Auto-Tuning Level is, found this: https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/description-tcp-features. The feature refers to the automatic setting of the TCP Receive window size.

I understand that this is the size of the receive buffer of the Windows TCP/IP stack. I understand that the size of a buffer can significantly affect the transfer speed. The window size is limited to WORD, so 65535 bytes in size. There is a scaling factor to enlarge the maximum to 1GB, that left-shifts the window size to the true buffer size. So total_buffer = window_size * 2^scaling_factor, from the article mentioned above.



And from https://docs.microsoft.com/en-us/windows-server/networking/technologies/network-subsystem/net-sub-performance-tuning-nics, the optimal buffer size between 100mbps and 10gbps is 64KB.



The obvious solution would be to directly change window size to 64KB right? But apparently that can’t be done, I don’t know how such a vital setting can’t be directly changed via Control Panel or Configuration. Apparently there also isn't a way to determine the current Window size and scaling factor. I do know that the default Window size in Windows 10, which is 17520 bytes, far from the 65535 mentioned above.



The options for "autotuninglevel" are:

disabled: Fix the receive window at its default value.

highlyrestricted: Allow the receive window to grow beyond its default value, but do so very conservatively.

restricted: Allow the receive window to grow beyond its default value, but limit such growth in some scenarios.

normal: Allow the receive window to grow to accommodate almost all scenarios.

experimental: Allow the receive window to grow to accommodate extreme scenarios. WARNING: This can dramatically degrade performance in common scenarios and should only be used for research purposes.



I also tried creating a DWORD registry value called TcpWindowSize as pointed in the first link in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters, to the desired value, 65535 or 0xffff in hex. After rebooting, as always, nothing changed. This registry value is supposed to set the Receive Window size.



Finally, it was time to try other autotuninglevel settings, I tried “experimental”, and that worked actually!for a couple of weeks. Now is the same yet again.



Last thing I tried is to set Tcp1323Opts, to 3, to “force window scaling and timestamps” as described inhttps://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/description-tcp-features#:~:text=The%20window%20scale%20option%20is,S%20is%20the%20scale%20value. But no change, as always.



So, I came to a point that when the speed lowers significantly, it was usually fixed with a reboot, but I’m still not happy with this crappy incomplete solution. This is the most annoying of all Windows problems I encountered so far quite a lot of problems actually. This apparent small problems and random issues is the kind of reason of why people are switching to Linux, but unfortunately, I can’t because I’m dependent on Windows-only software. If I wasn’t, I would be on Linux since Windows 8.



Thanks for whoever reads this whole thing, and I implore those above to make a change, fix windows, make it consistent, eliminate bloatware and stuff from the Windows 7 era. I’m talking about completely rewriting the OS, just like they did with NT 3.1, when Microsoft threw the DOS kernel away, and built a modern, much more stable kernel from scratch. And from there built all the other OS components consistently with each other, with very clean and debugged code. That is what I think would be best for windows right now, throwing all the pre-Windows 8 inherited stuff, and remaking the OS and all its components from the ground up, so they are consistent and clean. I hope this makes a change, and luckily, make Windows better.



If you have any ideas for my specific issue, please post here.



- Attentively, a user forced to hate Windows because its issues, but feels sad about having to. I really want Windows to get better.

:)

 

Windows 10 Pro Internet Speed Limitation?

Hi guys.
I've had to mark this as unresolved and bring it back up as the issue has returned. I am not sure what it is that is causing this as I haven't installed any program that would limit, manage/handle bandwidth usage.
Below are a few screenshots of my Programs and Features list and the list of Windows Updates:








To also note; I have done a few speedtests and the result is the same as before I reinstalled Windows. (100-144Mbps) After reinstalling, for a few weeks I was getting my full speed. (380Mbps) Then it suddenly capped. My iPhone XR (being connected to my 5GHz WiFi network) gets the full speed.

I have also redone the "tweaks" for trying to remove the limitation as in tutorials on Google. No help. None of these "fixes" actually work. That is to say; updating my network card driver (in this case my TP-Link TG-3468 Gigabit Ethernet PCI card), using Command Prompt with the few commands suggested to use, GPEdit.msc, etc. None of these work. Windows 10 is still limiting/capping my Internet and it is beyond frustrating. Delivery Optimization is also disabled and Limit Reservable Bandwidth in QoS Packet Scheduler is set to 0%.

I should also note that my Private Internet Access VPN is disabled.

- - - Updated - - -

Update: Typing this into an elevated command prompt seemed to allow me to use more of my speed, but not 350Mbps+.

I'm assuming it is peak times at the moment.

 

Upload speed capped on windows 10

Okay so, for some unknown reason, my computer and brand new laptop both running on windows 10 home, are capping my upload speed at 7.9mbps (exactly 0.6mbps from my router's upload sync speed). At first it may seem normal to be running slightly lower than
the upload sync speed, however on all my mobile phone devices, speed tests show that my phones are reaching between 9-10mbps. The exact same speed tests (And other speed tests) on my computer and new laptop show that the upload speed is being capped at 7.9mbps.

The router is new. I have recently had the line fixed so there's no issue there. The fact that my new out of the box laptop is also capping it makes me believe there's no malware or virus issue going on here. The only thing I have narrowed it down to is
that Windows itself is capping the speed somehow. I have also tried connecting to the router via ethernet cable however the speed is still capping at 7.9mbps. It is ALWAYS capping 0.6mbps under the sync speed and I'm not sure what is causing it.

 

Windows 10 Pro Capping Internet Speed

So this is the same thread as my previous one, but I have done a fresh install but this time Windows 10 Pro using the Windows Install Creator Tool that Microsoft Provides.

Before and after installing my AV, I was getting close to 500mbps. But after I installed all the updates for Windows, it went back to almost hitting 300mbps.

I will strike out the things that I haven't tried on this FRESH CLEAN INSTALL.

I've got a Gigabit Internet Connection with my ISP, but Windows seems to be capping the speed to no more than 300mbps. I know that it is Windows because when I do a speed test on the same machine, but using Linux instead, I get around 960-980mbps.

Integrated Ethernet Controller I218-V (Gigabit)

Connection Speed is 1000 at full duplex

• I've updated the controller (Downloaded from Intel website)
• Manually went through every device in device manager and updated each driver (Yes ALL devices by right clicking on and selecting update driver.. Yes there was probably over 200 of them)
• I've uninstalled the controller, reinstalled it then did ipconfig /flushdnns and ipconfig /renew
• I've tried disabling my AV and totally removing it
• I believe I have tried in Safe Mode with Networking
• I've checked to see if anything else was using my bandwidth to of which nothing was
• I've ran the network troubleshooter and no problems were detected
• I've manually configured the ip settings
• I've disabled all adapters except the ethernet one
• I've tried through Wi-Fi
• I've reserved an ip address in my router (I would assume that my mac address still the same after the install and that I wouldn't have to reserve the ip again)
• Tried different servers when doing the speed test
• I've tried google speed test and the speed test my ISP offers
• I've called someone from my ISP to come and look to see if there was a connection problem in the wiring
• Windows is on an NVME as is Chrome
• I've ran sfc
• I've disabled all services except Windows ones
• I've changed some settings that you can change through netsh (Followed guide)
• I've tried Edge
• I've tried incognito
• I've disabled all protocols except ipv4 and ipv6
• I've tried with just ipv4 enabled (Trying with just ipv6 was inconclusive)

i7-6850k

GTX 1080Ti

32GB DDR4 3600Mhz

Windows is updated to the latest

HELP ME! I'M DESPERATE!