Accelerating eMule

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Accelerating eMule

Post by ARCH »

Accelerating eMule

1. [goto=1]Why does eMule appear to be slow?[/goto]

2. [goto=2]Understanding eMule’s Credit System[/goto]

3. [goto=3]Managing your download queues effeciently[/goto]

4. [goto=4]Connecting to Kademlia "KAD" for more sources[/goto]

[list][anchor=1]1. Why does eMule appear to be slow?[/anchor][/list][/color]

eMule is a sharing, not trading client. It doesn’t take how fast it uploads a file to the next client as highest priority; instead it ensures that all connected clients are also participating in sharing that file, doing so in a fashion that prolongs its life. eMule is designed to allow everyone on the network to finish downloading files even when some of the sources or the original source go offline. That is why the eD2k network still stands strong although it is a public network, because it is self-maintained and very reliable.

But I didn’t write this guide just to ask you to live with it! While eMule might not start with a blazing speed, it will eventually pickup if you know your stuff – if you drive it well – which is what the rest of this guide is all about.

Note: I am going to assume that you already have eMule configured correctly; if not then you shouldn’t be reading this yet.

Go through the Configuring & Troubleshooting eMule guide then come back.

What are the factors that influence speed?

a. Number of sources

More sources means downloads will more likely start faster, and also means you will likely download from multiple users simultaneously, thus increasing the overall download speed. When you make an eD2k search, sort the results by availability and choose the one with most sources, but make sure it has at least 10% complete sources.

The screenshot below is an example of an eD2k local search of “click 2006 DVDRip”, with results sorted by availability. All files with a reasonable number of sources are in blue, while the ones with little sources (availability equals 5 or less) are in black. The second result is in green only because I have previously downloaded that file. Anyway, that’s the one you would want to download, because it has 48 sources (and equally importantly 39 full sources). Although the first file has a lot more sources, I haven’t downloaded it because it is Italian not English as you can see from the file name.


b. Download & Upload Priority

The download priority setting is simply responsible for allocating bandwidth to your downloading files. Let’s assume you are downloading two files, each with plenty of sources. If both files have an auto download priority, eMule will set them as Low Download priority and will try to divide the download bandwidth equally amongst them. If you want one of the files to download faster, make sure you are on the Transfers page, right click the file, choose priority (download) and select High – eMule will then try to allocate more download bandwidth to that file instead.

There is a very good reason why eMule assigns low download priorities for both of those files with plenty sources. If you add a third file with little sources later on, eMule will assign an auto high download priority to it. It is logical for eMule to want to download the files with fewer sources faster, firstly because it helps with sharing this file, and finally because the chances of completing the file are much lower.

By looking at the screenshot below, it is easy to find out that files with plenty of sources (like pirates) will download very quickly regardless, because there are simply too many sources compared to other with fewer downloads. However, as soon as the file with fewer sources (and high download priority) connects to a high speed uploading client, eMule will use most of your bandwidth to download that file, even if the other files (with low download priority) have much more sources.


On the other hand, upload priority does NOT control upload speed – it only controls how fast clients progress in your queue for each file. A file with an upload priority set to high or release means those users who are asking to download this file will have an advantage moving in your queue than other users who are requesting your files with Low or very low upload priority. You can change your file upload priorities from your eMule Shared Files page.


I recommend that you leave both download and upload priorities set to AUTO for all files. However, if you specifically want a file to finish as soon as possible, then you can simply set its upload priority to release, and its download priority to high, and then set all other files download & priorities to low/very low. After you finish downloading file, change all file download and upload priorities back to AUTO.

c. Patching your TCPIP.SYS

Windows XP Service Pack 2 comes with a security measure that limits the number of simultaneous incomplete outbound TCP connection attempts (half-open connections) per second to 10 (which was previously unlimited), which greatly downgrades P2P performance – patching TCPIP.SYS will increase that limit. We have a guide specifically for that purpose, explaining the new limitation imposed by Windows, its effect on P2P performance, and how to safely patch your system.

Click --> guide: PATCHING TCPIP.SYS and how it affects P2P performance

[list][anchor=2]2. Understanding eMule’s Credit System[/anchor][/list][/color]

What is eMule’s credit system?

eMule uses a credit system to reward those who contribute to the eD2k network. The more you upload to a client, and the more time you have waited in queue, the faster you advance in its queue. For that reason eMule requires more uptime than other p2p networks.

Credits are calculated locally not globally, thus everything that follows on this guide is a client-to-client relationship, not a client-to-network one. Basically, uploading to a client will resulting in gaining credits with only that client, meaning you progress faster only in his queue. That is a reason why sharing only your partial downloading files is the fastest way to download, though it isn’t as efficient in the long run if you are an eMule dedicated user.

It is impossible to see your credits because they are stored on the client that owes you those credits. As for the credits that you owe others, they are stored in the clients.met file. It was designed in this way to prevent hacking the credits on your client and unfairly tweaking it.

Let’s examine the factors that help you download faster, or more accurately, get you an upload slot on other clients more quickly.

How do I progress faster in my peer client queue?

a. The time you have been waiting in queue – don’t disconnect for more than 1 hour
b. The file upload priority at the remote client – you have no control of that
c. How much you upload (credits you earned) – upload the fastest you can without exceeding 80% of total upload bandwidth

When all of those 3 factors are maximized, you get the best speed experience.

Note: If you have to shut eMule for any reason (like restarting your computer), you have about one hour before losing your position at peer clients’ queues. Your sources will be lost in both cases, but they will easily be found back because those clients will communicate with you anyway. Shutting eMule more than 1 hour risks your peer clients failing to communicate with you and thus removing you from queue. It is also important to understand that you do not lose your credits if you shut eMule. Peer clients store your credits and only remove them if they don’t connect to you for a very long period of time (months).

[list][anchor=3]3. Managing your download queues efficiently[/anchor][/list][/color]

Generally speaking, eMule works best when you queue a lot of files, usually from 8 to 30. It sometimes depends on your upload connection though. If you have a 256kbps upload bandwidth or less, I'd say 20 is the maximum you should try having at one time.

Before I go on to explain the best approach for download queues, you need to understand the difference between Rating and Score. eMule uses Rating & Score to calculate how fast you will progress in queues and start the download. In very basic words, rating is calculated by much you upload, and score is calculated by how long you have waited in queue and also taking the rating into account.

If you want to maximize your score, you should queue many downloads AND keep your eMule connected all the time. You are staying in line for many files simultaneously; your score is getting higher for all them at the same time. Very simply, waiting for 1 file for 10 hours will yield 100 score for that file, while waiting 10 hours for 10 files will yield 100 score for each, 100x10=1000, which is clearly a big advantage. If you keep disconnecting your eMule however, your score will greatly suffer, and performance will be downgraded.

Alternatively, you could only queue around 4 files, relying more on rating than score. Uploading those 4 files is much faster than uploading 20 files. It's like you're exchanging with fewer people, but faster. You are relying on how much (and how quickly) you are uploading to them, not how much time you are waiting in their queue. However, although you might finish 4 queued downloads faster than say 20 queued downloads, it is much less efficient overall.

Efficient downloading means queuing many downloads and not be concerned for time – eMule works best as with set & forget approach!

Note: If you stop a download the sources will be deleted. That can be helpful when you want to resume your download in a few days, or basically after a long period of time, instead of uselessly reserving those sources and using up your max sources, you would give it to something else. Pausing the download however keeps the sources for a limited time (about one hour), enough for you to resume more quickly while they are still saved, useful when you plan to resume downloads shortly afterwards. Since sources change all the time, keeping them for a long time is not recommended anyway.

[list][anchor=4]4. Connecting to Kademlia "KAD" for more sources[/anchor][/list][/color]

This part has moved - click here to read about KAD.

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