BitTorrent Clients

Most people complain that downloading using BitTorrent in the background slows down their PC. This is true to some extent. Generally, it depends on what client you are using. Client like Azureus is based on Java and it takes up alot of memory space; it eats up your system RAM like there is no tommorrow.

Some BitTorrent clients:

µTorrent
Azureus
BitComet
BitLord
BitTornado
G3 Torrent

I have tried various BitTorrent clients, and I found µTorrent the best (screen-shot below). It is light-weight, skinnable and requires no installation; you simply download the executable file from the website, put it in a folder, and run it.

The good thing about µTorrent is that it saves your preferences and data into a file in the folder; it is independent of your system registry and folders. So assuming if you want to format your computer, you need not worry about installing it back and configuring it back. The screenshot below is how my µTorrent folder looks like.

Each of the file serves a purpose, explained below:
µTorrent.exe – the executable file
toolbar.bmp – Skin file
tstatus.bmp – Skin file
dht.dat – uTorrent’s DHT data
resume.dat – your torrent progress
settings.dat – your torrent client preferences

And that is it to your µTorrent client! All in less than 1MB!

P.S. I will discuss more on µTorrent later.

Firewall must allow BitTorrent Traffic

Make sure your firewall do not block BitTorrent traffic. It is of no use, if you properly tweak your BitTorrent client, just to find out that your firwall is the culprit for limitting your BitTorrent client.

If you are using Windows XP’s default Firewall, Go to:

Start > Control Panel > Windows Firewall > Exceptions

Than add your BitTorrent client execute file to trusted programs, and the ports you configured.

I strongly discourage using Windows XP Firewall. Get a decent software firewall like Comodo Personal Firewall, PC Tools Firewall, or Sygate Personal Fiewall (discontinued product). These are free and much better than the one that came installed with Windows XP SP2.

Another way is to use a combination of both software and hardware firewall. The hardware firewall I am referring to is your wireless router (this feature is nowadays found on most wireless routers).

Cap your Upload Limit

Cap your upload Limit your upload speed to approximately 70% of your maximum upload rate.

First of all, test your connection speed. One good website for this is SpeedTest. Here is a screen shot of my connection.

Do note that SpeedTest list its results in kilobits. Since 8 bits = 1 Byte, simply divide the value by 8.

My connection is rated at:

8178 kilobits (download) and 248 kilobits (upload) or

1022.25 kiloBytes (download) and 31 kiloBytes (upload)

From here, change your maximum upload speed to 70% of your upload speed. For my connection, my upload speed should be ~20kB/s. But since I am on cable connection, I limit it further down to 10kB/s.

Do not get me wrong, everyone should share as much as possible. But if your upload rate reached is at its limit, your download rate suffers significantly.

But do not limit your download speed! The logic that by telling your BitTorrent client to reach its limited threshold is nonsense! Doing so only limits your potential download speed.

Also, if your upload is set to 15kB/s and your download is 50 times faster (in my case), do not expect your download to be maxed out every time! In fact, a realistic expectation for a well-seeded torrent (a swarm with many seeds and few peers) would still be around 80% your download speeds, i.e. 815kB/s for mine.

But for most of my torrents found in private websites (like BitSoup, FileList, TorrentBytes), my speed wwill be better than 815kBps. Here’s a screenshot.

Remember that this speed would be reached in an ideal, well-seeded torrent, but unfortunately, this is usually not the case with public trackers; where leechers far outnumber the few poor seeders trying, to keep the torrent going.

For such cases, I cannot help. This guide is only meant to optimize your BitTorrent client, not the BitTorrent protocol itself.

Change the Default Port in BitTorrent Client

By default, all BitTorrent client uses port 6881-6999. Since BitTorrent accounts for a lot of the total internet traffic, your Internet Service Provider like to limit the connection offered on these ports. Since most BitTorrent client allow you to change the ports to another range, just choose anything you like.

Typically, I would choose a number between 1024-65536. For example, 5555-5559 or 8880-8889. Never choose a wide range like 5555-7777. This may result in slowing down your connection, rather than optimizing it.

2 things to take note if you are behind a router:

1) Ensure that you have the ports forwarded in your router.

This can be done from your router web interface. Enter any name for the Application field (this is for your reference); enter your port range (for example 5555-5559); set to both TCP and UDP for under the Protocol; forward to the IP address you want to port forward to. Do remember to check the “Enable”, else it will not port forward!

2) Uncheck “Randomise port each time uTorrent starts”.

Leaving this option checked will use a different port every time you launch the BitTorrent client, resulting in improper BitTorrent port forwarding through your router.

For example: You port-forward port 5555-5559, and left the randomise option checked. Each time you start the BitTorrent client, it chooses a number from 1024-65536. You may define it through the configuration menu shown above, but if you exit the client and re-launch it, the port will change.

Check the Available Number of Seeds and Peers

Check Seeds and Peers

An effective gauge, but often overlooked.

People always complain:
“I cannot get high speeds and I’ve done everything you advised me to do. Why is it so?”

The first thing I would ask is:
“How many seed and peers are you connected to?”

And he would answer:
“I’m not so certain. Let me check.”
*Couple of minutes later*
“Oh… 1 seed and 25 peers.”

Of course your speed is not good! Just look at your seed:peer ratio! It is horrible!

Wait a minute. What is a peer?

A peer is another computer on the internet that is sharing the file you wish to download. Typically a peer does not have the complete file; if it did it would be called a seed. Peers are also called leeches, to distinguish them from those who have completed their download and continue to leave their BitTorrent Client running and act as a seed.

Ok. So what is a seed?

Well, a seed is a user that has a complete copy of the specific torrent you are downloading. Once your client finishes downloading, it will remain open until you stop it. This is known as seeding.

You can also start a BitTorrent Client with a complete file, and once BitTorrent has checked the file, it will connect and seed the file to others.

It is good to continue seeding a file after you have finished downloading, to help others download faster.

Also, when a new torrent is posted to a tracker, someone must seed it in order for it to be available to others.

From the above case, it is likely that my friend must have just download a torrent that is just posted on a tracker, since the number of seeders is 1.

A rule of thumb is to always check the torrent’s current seeds and peers. The more seeds (compared to peers) the better.

Hence, a torrent with 50 seeds and 50 peers (1:1) is better than 50 seeds with 100 peers (1:2).

Patch Half-Open TCP Connection

Microsoft Windows XP Service Pack 2 introduces a limited TCP connection, which is set to a maximum of 10 (the previous limit was over 65,000). This is “supposed” to protect the host PC from connecting to a high amount of random IP numbers.

Since some malicious worms could spread by connecting to a high amount of random IP numbers, Microsoft, in their infinite wisdom, introduced a patch in SP2 to limit the TCP connection to 10.

Regrettably, this also slows down application that relies on many connections (such as the BitTorrent client). This limit has the potential to cause slowdowns in certain situations.

An unofficial patch will modify the locked tcpip.sys and let you set the limit to whatever you wish. 75 half-open connections is a reasonable limit or you can set the limit back to 65,535 which it was before the SP2. The patch is called EventID 4226 Patcher and can be found on LVL Lord’s web site.

Just bear in mind that every time you update Windows, it will revert back to the original connection number (i.e. 10). So my recommendation is that once you have updated Windows, run the patcher again to change the number of maximum connection.