Windows 7 TCP RWIN

[squid13]

Is there a way to set the RWIN on windows 7. The auto tunning is set to normal but the Tweak Test at DSL and the test at Speed Guide tell me it's set wrong. I feel if it was set right I would get more out of my broadband. I have Cox preferred which is 10Mbps down and 768 Kbps up. With power boost it's 12.5 Mbps and 1Kbps. RWIN now is 65536 and should be set higher according to those test.

 

[Casca]

Vista and 7 adjust this (and related values) dynamically. The test site is a static read and not indicative of your overall range of settings.

 

[Sanvean]

I have been a member of DslReports since 2001 and it's advised to let Windows 7 (just like Vista) do it's job.
As Casa pointed out, it's dynamic, Win7 doesn't have registry keys like XP that can be tweaked.

 

[squid13]

Ok I'll leave as is.

 

[streetwolf]

Good info here:

SpeedGuide.net :: Windows 7, Vista, 2008 Tweaks

 

[squid13]

streetwolf Thank You for that article it was very interesting reading. Installed that patch and it showed a mark improvment.

 

[Lobin77]

I believe RWIN Autoscaling in Windows 7 is wrong (Miscalculated)!
And the SG TCP/IP Analyzer test site (Connection Diagnostics) confirms this!
Also, on SpeedGuide configuration pages and people talking on forums, for example the Mozilla Support Forum (888273 - RWIN Scaling (RFC1323) limited to 2 on Windows 7 and 8), from 10 years ago (2013), also confirmed a wrong calculation by Mozilla, BUT with the same Windows Limit numbers! And on that Forum they said that Chrome and IE were doing it right with "window scale" of "8" Limit of 8 with "Window Scale" different from Mozilla and Windows 7: "Chrome and IE10 use a window scale of 8 and Firefox a window scale of 2. But on Windows 7 with other software installed, debugging this becomes a little tricky (as you discovered Windows like to change things dynamically)."

So yes, there is a high probability that it was Calculated Wrong BEFORE!
And now Windows 8 and 10 don't support this limit per RWIN! Source: SG :: TCP Optimizer 4 Documentation - Windows 7, 8, 10, 2012-2019 Server
Website texts: "Under newer Windows OSes, it may change the auto-tuning algorithm (restricted for speeds under 1Mbps, normal for most broadband connections, experimental for speeds over 1 Gbps, to be used with caution currently)"
"Even though the TCP Receive Window value can't be modified directly in modern Windows variants, you can still adjust how aggressively the TCP auto-tuning algorithm increases the RWIN value."

Conclusion: This suggests that the "Receipt Window Scale" Changes were inaccurate, and therefore they began to use/create more complex algorithms to improve the Receiving Stability of this "Receipt Window Scale" of packets on the Network!
I hope I didn't get your hopes up.. But because really... you can still set the option "restricted: somewhat restricted growth of the Tcp Receive Window beyond its default value" to the "autotuninglevel", that is, to the "TCP Window Auto-Tuning" in the SG TCP Optimizer from www.speedguide.net!
Or using command in CMD:

netsh int tcp set global autotuninglevel=[B]restricted[/B]

Byee

 

[file3456]

I hope I didn't get your hopes up

Probably not since this thread is 13 years old.

I have a half gig download speed and don't have to tweak anything. Others have a full on 1 Gig download speed and don't have to tweak anything.

This tweak crap was more popular in the days of XP and dial-up or slower broadband connections trying desperately to get more than what the ISP provides. There exists browser config improvements as well but are no longer necessary unless you use very slow Internet. Just by blocking Ads alone will help in that department...