The RAR Argument
Note: An interesting solution to extracted files has recently arisen, which lets you recompress extracted files into their original .RAR files! Read about it here!
This argument is taken from the point of view of BitTorrent P2P users. At the source of the scene, there is little argument, and the scene rules specify the format that the RAR archives should take. However, when it comes to BitTorrent, there is often debate as to whether to use RARs or not. In the end, it’s up to the individual.
Having read the following arguments, please let us know what you prefer in the comments!
CONSIDERATION OF THE SCENE
Archive Compression Ratio – Argument favours RARed
This is a very simple argument – RAR archives compress files, and as such save space and bandwdth. The counter argument would be that most files are already compressed, for instance in MP3 format, or using some video codec, so the extent to which the compression occurs is not very large. (You cannot much compress a pre-compressed video or audio file, but you can greatly reduce the size of documents and progams, for instance, by RARing them). Either way, a small compression is still a compression!
Seed Longevity – Argument favours unRARed
When a peer completes the download of a RARed high definition movie, for instance, he will be inclined to extract the movie files and watch it. Once extracted, he has two complete versions of the release on his hard drive, and unless he is a very loyal seeder, he will be inclined to delete the one which he cannot immediately use – the RARed one.
Low Disk Space – Argument favours unRARed
In order to use the files downloaded in RARed format, you must (almost always) extract them. This causes approximately double the disk space to be used (unless you delete the RARed files after use – see “Seed Longevity”). For this reason, downloading unRARed files means more space is needed to use the files. For very large torrents, where the available space does not exceed twice the size of the compressed torrent files, it can be impossible for completed users to extract the files.
FAT 32 and old filesystems – Argument slightly favours RARed (as long as they’re split)
The thing to know about FAT32 is that the maximum file-size limit is 4 GB. For this reason, large files over this size can only be saved on these disks if split, for instance into multiple RAR archives. The thing is, users of this file system would have to extract the large file in order to watch it anyway. Therefore they must have access to a NTFS or similar disk, that does not have this limit – so why not download directly to that disk in the first place? This is only an issue when the NTFS disk in this example is external or network-connected, and not always turned on – then it would not be possible to seed or download for long periods of time.
Disk Fragmentation – Argument favours splitRARs with windows, otherwise unRARed
With windows operating systems, which use hard disks inefficiently, small files run less risk of becoming defragmented. Thus having split RAR archives prevents fragmentation from the start, and also helps when defragmenting. For unix based systems, this is not an issue, since they repair fragmentation on-the-fly, rather than making it worse with every file transfer.
Portability to other trackers – Argument favours RARed
Often peers find themselves wanting to download a file or set of files from one tracker, and either uploading or aiding seeding on another tracker. However, if they download a scene release as unRARed from one tracker, and the other tracker has it in RARed form, then they cannot seed to that tracker without first downloading it as RAR parts. For this reason, users may rather have the split format, since they could always unRAR it themselves, and so have the flexibility to seed wherever they choose.
File Selection – Argument favours unRARed
A useful feature of most BitTorrent clients is the ability to choose which files are downloaded, and which are not. If a selection of files is packed into one or more RAR archives, it is impossible to get the files you’re after until you’ve downloaded the entire torrent.
SeedBoxes and FTP – Argument favours RARed
Many uploaders on pivate trackers use Seed Boxes to quickly upload files to many people, and to improve their ratio by using the enhanced upload speed that they provide. However, the files still have to be transferred to the users computer in order to watch the film, or to save it locally. This process is easier when large files are split into many smaller parts, because should a part become corrupted during the transfer process, a user must only re-download that part. Otherwise, they’d have to re-download the entire file should an error occur, or a file be corrupt.
Extracting – Argument favours unRARed
Why should every peer spend time extracting RAR archives, rather than the initial uploader spending that time instead? As soon as two people complete the torrent, the total time wasted is twice that it would have been, had the uploader unRARed. From an efficiency point of view, it seems obvious that the uploader should spend the time. However, we should also consider the value of each person’s time. The uploader’s time is much more important than that of his peers, because he could be spending it uploading more files. If he has to spend time extracting, he might not be able to upload as much.
File-Hosting Sites – Argument favours RARed
Uploading on services such as RapidShare, FileFactory and ShareBee requires large files to be split into several smaller RAR parts before being uploaded. For this reason you’re much more likely to be able to find missing parts of a release on the internet, should the torrent die, for instance. There is only a small probability that it’ll help at all, but one thing’s for sure – you cannot easily download very large unRARed releases from these sites.
PAR – Argument rafours RARed
The use of PAR, or “Parchive” – .par and .par2 files alongside the set or RAR archives allows users to make use of the split RARs even if one had become corrupted, by using the PAR file to create a replacement RAR section. Read all about it at Wikipedia:Parchive.
Pre-Times – Argument favours neither
The fact that the uploader might have to unRAR the files, means that everyone has to wait an extra 5 minutes before being able to download the torrent. However, they do not then have to extract it themselves, which would take them 5 minutes anyway. The question is, would you rather have the files saved faster, but not be able to use them immediately, or would you prefer waiting a few more minutes to have immediately-usable files once they had downloaded? [What is a pretime, anyway?]
The overall argument for using RARs with BitTorrent is probably favoured towards NOT using them. Doing this allows various useful features of the torrent protocol to be used effectively. Namely file-selection and handling of piece-corruption. From a productivity and torrent health point of view however, it makes sense for the uploader to extract the files prior to uploading them. As stated at the beginning of this article, it comes down to personal preference at the end of the day anyway.
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