How to Optimize your Bittorrent Speeds

[Chiups]

1. Hack the max half-open TCP connections

If you’re on XP sp2, your TCP connections are limited to a maximum of 10. This might hurt your downloading speed because it wont let you connect to as much peers as you want. It is supposed to slow down viruses because their spreading strategy is to connect to a high amount of ip numbers, but it could cripple your torrent downloads.

A nice way to fix this is to download this patch.

Note: Some people report that their antivir reports the patch to be a Virus, This is not the case. Check out http://www.lvllord.de/ for more details on this

The patch allows you to set the maximum allowed connections to any number you want. Any number between 50 and 100 is ok (more is NOT always better).

Next you need to configure your torrent client to allow 50-100 max half-open TCP connections

uTorrent: Options > Preferences > Advanced options > net.max_halfopen



Bitcomet: Options > Preferences > Connection > max half-open TCP



Now you’re ready to go…

A third point of interest is that some “windows updates” revert your tweaked tcp connections back to 10. So it’s wise to check this every now and then. You can check this by going to (in windows xp) Start > Control Panel > Administrative Tools > Event Viewer > System… Look for event 4226 (sort by event).



For more details about Windows XP SP2 and Event ID 4226 read David Kaspar’s excellent post

If there are a lot of daily occurrences it’s likely that the max amount of half-open tcp connections was set back to 10. Or you’re infected with some nasty spyware…

2. Torrent Client Configuration

In order to apply these tips you need to know your maximum up- and download speed. You can test your bandwidth over here (stop all download activity while testing). Also make sure that you applied the tips provided in our previous posts.

Note that there’s a difference between kb/s (kilobits/second) and kB/s (kilobytes/second). To be precise, kB/s = kb/s divided by 8. In this tutorial we use kB/s (like most torrent clients do). This means that you might need to calculate your max speed in kB/s yourself if the speedtest only gives you the results in kb\s (so divide by 8 then).

Settings 1-4 can be found in the options, settings or preference tab of most torrent clients.

1. Maximum upload speed

Probably the most important setting there is. Your connection is (sort of) like a pipeline, if you use you maximum upload speed there’s not enough space left for the files you are downloading. So you have to cap your upload speed.

Use the following formula to determine your optimal upload speed…

80% of your maximum upload speed

so if your maximum upload speed is 40 kB/s, the optimal upload rate is 32kB/s

But keep seeding!

2. Maximum download speed

Although setting your maximum download speed to unlimited may sound interesting, in reality it will only hurt your connection. If you still want to be able to browse properly, set your maximum download speed to:

95% of your maximum download speed

so if your maximum download speed is 400 kB/s, the optimal download speed is 380kB/s

3. Maximum connected peers per torrent

Yet another setting that you don’t want to max out. I experimented quite a lot with the max connected peers settings and came to the conclusion that both high and low number hurt the download speed of a torrent. The following setting worked best for me.

upload speed * 1.3

so if your maximum upload speed is 40 kB/s, the optimal amount of connected peers per torrent is

40 * 1.3 = 52

I didn’t noticed a difference for fast or slow connections here.

4. Maximum upload slots

1 + (upload speed / 6)

so if your maximum upload speed is 30 kB/s, the optimal number of upload slots is

1 + (30 / 6) = 6


3. More Tips

Check seeds and peers
A simple tip, but very important. Always look for torrents with the best seed/peer ratio. The more seeds (compared to peers) the better (in general). So 50 seeds and 50 peers is better than 500 seeds and 1000 peers. So, be selective.

Change the default port.
By default, BitTorrent uses a port 6881-6999. BitTorrent generates a lot traffic (1/3), so isp’s like to limit the connection offered on the these ports. So, you should change these to another range. Good clients allow you to do this, just choose anything you like. If you’re behind a router, make sure you have your ports forwarded (www.portforward.com) or UPnP enabled.

Disable Windows Firewall
It sucks. Windows Firewall hates P2P and often leads a life of it’s own. So disable it and get yourself a decent (free) firewall, Kerio or Zone Alarm for example.

Turn on Encryption
Encrypting your torrents will prevent throttling ISP’s from limiting your BitTorrent traffic. Check out how to enable encryption in Azureus, uTorrent, and Bitcomet, the three most popular torrent clients.

Optimize your internet connection
The TCP optimizer is a freeware utility that optimizes your internet connection. I found it very useful and it helped speeding up my connection for regular internet activity and for downloading torrents. Just download it, and move the slidebar to your maximum download rate (note that it’s in kb/s). Don’t try to set it higher because that will hurt your download speeds!

Last but not least… Buy a faster connection…

Happy Torrenting!

(Credit goes to: torrentfreak.com

[kidart451]

Thanks for the tips man!

[jackluo923]

They forgot to add the following to avoid confusions:

1) kB does not equal to kb. 1kB = 8kb. So when you caculate your internet bandwidth, divide your speed by 8 to get the kB number.

For example: My internet gets 5000kb/s download speed on speedtest.net
I divide the number by 8 which gets me 625kB/s. 625 is my actually download, not 5000kb/s.

utorrent and many other torrent client uses the kB format instead of the kb format.

2) Seeding 80% of your upload speed often will result in slower download speed. The best upload stradegy is to seed as many different torrent as possible. Set the uploading cap for each torrent to 5kB/s. Set the upload cap for gobal upload to around 30-50kB depending on your internet bandwidth.

When you use the above method to upload, you'lll get much better speed.

Normally, i get around 300-500kB/s for each torrent. My internet download speed max up around 600kB/s during the day and 1000kB/s at night.

[Stuart]

Would this work with vista? Im guessing yes..

[jackluo923]

You should try the TCP Optimizer from Speedgude.net

http://www.speedguide.net/files/TCPOptimizer.exe

The program might work on Vista. TCPOptimizer is much more useful than lvllord's method.

[firecube134]

Totally crashed my internet. I'm going to have to reformat to fix the tcpip now. DO NOT INSTALL JUST LEAVE EVERYTHING BE.

[MemphisMasenko]

Originally Posted by firecube134

Totally crashed my internet. I'm going to have to reformat to fix the tcpip now. DO NOT INSTALL JUST LEAVE EVERYTHING BE.

Thats cool of you to warn folks.
plus rep.

[Chiups]

Originally Posted by firecube134

Totally crashed my internet. I'm going to have to reformat to fix the tcpip now. DO NOT INSTALL JUST LEAVE EVERYTHING BE.

Or maybe you did something wrong? Im sure there would have been a complaint before....

[firecube134]

I know I didn't do anything wrong, I followed every instruction exactly, the link you gave provides a download area for the 'Patch' and there are many posts saying to disregard that your virus checker shows it as a virus for editing the tcp/ip part of your registry, even if it isn't a virus, it completely crashed my internet, I did the speed test before modified anything (i'm through comcast) and my download was 8000 kbps and after I installed the patch and edited the settings it dropped clear down to at most 1200, Just let it be and let it take longer to download, leave it on while you sleep. Do Not Edit the Registry. (System restore doesn't restore it, only fix was for me to completely reformat)

[Chiups]

For one, you should ALWAYS backup your registry before editing it, thats common knowledge. Im not quite sure about the rest, you may be right who knows...

[firecube134]

"for one" lol don't be a punk. I did back up my registry and it didn't actually set it back to the original settings, I even downloaded several registry and tcp/ip reset tools to try to reset it and none of them truly worked. And if you should "Always" back up your registry why did you not include it on your Detailed list of instructions? All you say is to download the patch, The patch doesn't tell you it edits your registry either, I figured that out after reading through the pages and pages of replies going back and forth whether it works or not on the download site.