Optimizing XP Registry - good idea?

[shaihulud]

The window is a frame of time in which bytes can be in transit without any acknowledgement. This is only beneficial when the networks are broad and high in latency. Many of networks have UNIX and Linux which auto tune the window during the three way handshake and if you were to capture the activity between the two hosts you would notice that the window is actually very small if such auto tuning hosts are used. Contrary to belief you will not gain anything and can lose more due to packet loss. However if something has changed your window to a lower amount then this can be beneficial.

Windows, when detecting a capable Ethernet device, will set the window to 65535 bytes. This is more than enough for most broadband networks. Because the packets that were in transit would have already arrived on low latency networks. Window Vista is auto tune too, similar to UNIX and Linux.

You may notice that they recommend a lower setting for you. This can be relative due to the fact of how networks work. I would leave it at the default that you have. This is as long as you have not made any changes.

Some things that can change the latency is a better and faster router, a better NIC (I always recommend Intel’s Ethernet solutions because of multiple OS driver support and excellent performance). And always, of course, a better ISP with excellent routing. Some may say one router is better than the other, be careful. This is very relative, and some that may make a suggestion are not capable of suggestion one.

[SRTDodge05]

If you do start changing things around make sure you write down the default settings in case you have a problem.

[Gorganzola]

Honestly, not worth the effort trying to find the settings. Leave it as is and do something better with your day.

If you want faster Internet then keep the computer clean and upgrade the speed by paying more money.

Most of the tweaks you will find out there are old and only enhanced pre-SP2 systems.

[SRTDodge05]

Originally Posted by Gorganzola

Honestly, not worth the effort trying to find the settings. Leave it as is and do something better with your day.

If you want faster Internet then keep the computer clean and upgrade the speed by paying more money.

Most of the tweaks you will find out there are old and only enhanced pre-SP2 systems.

I agree, if it isnt too much more i would pay for little faster internet speed. Not really anything you can do to make your internet faster with OS tweaks.

[polonyc2]

I disagree with most of the responses here...registry tweak programs in general I would stay away from, especially those that change a whole bunch of settings without telling you what they all are

but...as far as internet speed tweaks...changing the default RWIN, especially on Windows machines can greatly improve your download speeds...the default RWIN is too low for those with broadband connections...after changing my RWIN and testing my speeds I definitely noticed an improvement

I use the Dr. TCP program (which is just a registry edit and not a program)---where the user inputs the RWIN and MTU and you can always change it back anytime you want

my current RWIN is 128480 and MTU is 1500

try these different RWIN values on your rig to determine your optimal setting: 64240, 128480, 256960 or 513920

[Spawn_abx]

I know this thread is a bit old, but I have a little to add.

My only broadband option is Hughesnet. Everything worked well, for the most part, before I used Dr. TCP.

I was looking for a tweak that would stabilize my downloads... This DW7000 loves to burst, then pause, then burst, then pause... Get the point?

After significantly lowering my MTU, streaming video and audio have stabilized a great deal, and Web pages load much faster... To be honest, I'm about to try using a VoIP application again, since my stabilizing attempts seem to have worked. VoIP being less that quality over satellite, I will test it AGAIN.

You may ask how I found the MTU settings. The newer self-hosted DW and HN modems used by Hughesnet have an advanced console I was made aware of while beta testing for them. The main page has the setting staring you in the face... LOL

I simply wanted to add my findings to this discussion!

[Spawn_abx]

Originally Posted by polonyc2

I disagree with most of the responses here...registry tweak programs in general I would stay away from, especially those that change a whole bunch of settings without telling you what they all are

but...as far as internet speed tweaks...changing the default RWIN, especially on Windows machines can greatly improve your download speeds...the default RWIN is too low for those with broadband connections...after changing my RWIN and testing my speeds I definitely noticed an improvement

I use the Dr. TCP program (which is just a registry edit and not a program)---where the user inputs the RWIN and MTU and you can always change it back anytime you want

my current RWIN is 128480 and MTU is 1500

try these different RWIN values on your rig to determine your optimal setting: 64240, 128480, 256960 or 513920

Thanks much for those RWIN settings! I have my MTU set @ 256Kbps and my RWIN set @ 513920.

My Inet connection with HN is stable instead of bursting, and video D/L and streaming Music work well together with these settings.

If there are any other HughesNet clients, you may want to test these settings for yourself. They work great on my older DW7000 system...
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12/4/2007
After ranting about this, I should be testing during the day. Video D/Ls are still a little slow during the day. All I have to do is raise the MTU and it works as before. The reason I chose 256Kbps: That is what the DW7000 modem receives at... Simply put, to gain in one aspect, you sacrifice in another.

I still say HughesNet is overcharging for their service; however, they're capitalizing on a niche market... At least I CAN watch a video!

[shaihulud]

With TCP there is no true optimal setting. This is why auto tuning stack is better due to the understanding between the hosts and their ability to communicate as they do so too. Setting your RWIN to an exuberant amount will not be beneficial unless you have a very long latent path to the communicating host. Remember RWIN is the amount of bytes in transit before acknowledgement. If the ACK has been received, due to low latency, it is not in the window anymore it is done. Having a high amount can actually waste memory and cause a higher reshuffle time if a packet is lost.

Note, an MTU cannot go over standard Ethernet size unless you are using jumbo frames. But this will only matter at your layer 2 level. When the packet leaves the WAN it will be standard Ethernet size, if the MTU is standard size also or the transmittable size the network requests. Having to lower your MTU means you have issues with your hardware or even network. This should never have to be done, even on PPPoE DSL networks (1492). Note lowering the MTU will lessen the performance of the network and will also make the computer work harder due to the need to transmit more packets. This is why jumbo frames can be beneficial to a host and is complemented by large send offloading.

I recommend leaving at default 65K RWIN and nothing else. Matching the multiple of the segment size to the RWIN does nothing too since transmission windows are out of the segment multiple. In other words, the RWIN does not need to be 64240, 128480, 256960 or 513920 for optimal configuration. Any time optimal configuration is used is usually/basically incorrect.. If you really want better performance I always recommend Intel’s Ethernet solutions and a capable router such as the DGL-4300. Basically and Ubicom based product.

As I said long ago, if you were to capture your packets in transit you will notice that the RWIN does not go that high, and never comes close to the some of you have configured. It may be shocking what you see the amount as because it is actually small. At 65k my test results at Speakeasy with no configuration just at default settings with Comcast Blast are: Download Speed: 34209 kbps (4276.1 KB/sec transfer rate) Upload Speed: 1443 kbps (180.4 KB/sec transfer rate)