RWIN tweaking

I would like to check and maybe tweak the RWIN registry value does anyone have any experience doing this on win7 rc (7100)?

torrentg said:

Vista and 7 both tune it dynamically. Hacks or changes on these OS are not recommended.

Read further here:

Tweaking for speed - dslreports.com

I have done the test there and it states vista has no tweakable TCP settings

but that I should set the RWIN to between 151008 and 400752

Meanwhile over at SpeedGuide.net :: The Broadband Guide

I get this result... (the site also recognizes my OS as windows 7!)

Default TCP Receive Window (RWIN) = 66792
RWIN Scaling (RFC1323) = 2 bits (scale factor: 2^2=4)
Unscaled TCP Receive Window = 16698

RWIN is not fully optimized (even though it is a comparatively large number). The unscaled RWIN value is lower than it should be. Also, RWIN being close to and above 65535 does not justify the header overhead of enabling TCP 1323 Options. You might want to use one of the recommended RWIN values below.

RWIN is a multiple of MSS
Other RWIN values that might work well with your current MTU/MSS:
63888 (up to 2 Mbit lines, depending on latency. MSS * 44)
127776 (1-5 Mbit lines, depending on latency. MSS * 44 * 2)
255552 (2-14 Mbit lines, depending on latency. MSS * 44 * 2^2)
511104 (8-30 Mbit lines, depending on latency. MSS * 44 * 2^3)
1022208 (25-60 Mbit lines depending on latency. MSS * 44 * 2^4)

I have tweaked my win xp using DRTCP from dslreports.com
and my connection is much faster...

just did a speed test at speedguide.net...

« SpeedGuide.net Speed Test Results »
12811 kbps down (~12.81 Mbps, 1564 KB/s)↓
962 kbps up (~0.96 Mbps, 117 KB/s)↑
10240 KB downloaded in 6.548 seconds
3072 KB uploaded in 26.168 seconds
Tested on: 2009.05.25 20:32 EDT
Tested from: street-spam.de
Latency: 132ms
Provider: dip.t-dialin.net
Location: Gau-Bischofsheim, DE

Speed @ 296% of the average for dip.t-dialin.net

my connection is advertised as DSL 16000 (whatever that means)

Hi guys,

Is there a way to set scale factor of window scaling RFC 1323 to 2^6=64 ?
In Windows 7 x64
Thanks !