ICH - Revision history

81.25.33.18: /* What are its results? */

2008-05-10T09:29:31Z

‎What are its results?

Ihmselbst at 13:19, 22 January 2006

2006-01-22T13:19:17Z

Ihmselbst at 12:01, 22 January 2006

2006-01-22T12:01:18Z

80.55.246.78: Language corrections.

2006-01-21T08:34:51Z

Language corrections.

84.169.70.227 at 18:11, 29 August 2005

2005-08-29T18:11:15Z

80.224.220.139 at 20:27, 14 March 2005

2005-03-14T20:27:24Z

209.123.215.104 at 18:03, 14 March 2005

2005-03-14T18:03:01Z

Jacobo221: corrupt links ;P

2004-10-20T01:23:08Z

corrupt links ;P

Jacobo221 at 22:47, 19 October 2004

2004-10-19T22:47:26Z

Jacobo221: in the meantime only

2004-10-02T22:34:45Z

in the meantime only

New page

While no info is available from ourselves, here is a reliable source to learn about this topic:

http://www.emule-project.net/home/perl/help.cgi?l=1&topic_id=589&rm=show_topic

@@ Line 16: / Line 16: @@
 == What are its results? ==
-The best that can happen with ICH is that the first 180KB in the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed ones. If so, only 180KB have to be redownloaded out of the 9.18MB the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is in size.
+The best that can happen with ICH is that the first 180KB in the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed ones. If so, only 180KB have to be redownloaded out of the 9.28MB the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is in size.
 The worst case should be when the last 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed bytes. In this case, the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] has to be redownloaded. Anyway, since redownloading the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] would have to be done anyway if ICH had been disabled, this is not a loss at all (except for some little CPU resources).

@@ Line 18: / Line 18: @@
 The best that can happen with ICH is that the first 180KB in the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed ones. If so, only 180KB have to be redownloaded out of the 9.18MB the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is in size.
-The worst case sould be when the last 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed bytes. In this case, the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] has to be redownloaded. Anyway, since redownloading the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] would have to be done anyway if ICH had been disabled, this is not a loss at all (except for some little CPU resources).
+The worst case should be when the last 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed bytes. In this case, the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] has to be redownloaded. Anyway, since redownloading the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] would have to be done anyway if ICH had been disabled, this is not a loss at all (except for some little CPU resources).
 == Is it useful? ==
@@ Line 26: / Line 26: @@
 == Is it CPU expensive? ==
-Not at all. On any modern CPU, hashing the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]]s takes less resources that you would imagine. Since it saves 50% corrputed data in average (and can even save up to 99%) and the hashing process is only done from time to time when necessary, the resources it makes use of are practically null.
+Not at all. On any modern CPU, hashing the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]]s takes less resources that you would imagine. Since it saves 50% corrupted data in average (and can even save up to 99%) and the hashing process is only done from time to time when necessary, the resources it makes use of are practically null.
 Even on old CPUs you should still take into consideration not disabling ICH, since the amount of CPU it takes, compared to the amount of [[corrupt]]ed data it might save, is far enough to keep it active.

← Older revision		Revision as of 12:01, 22 January 2006
Line 1:		Line 1:
		+	<center>
		+	'''English''' \| [[ICH-de\|Deutsch]]
		+	</center>
		+
	== Description ==		== Description ==

@@ Line 10: / Line 10: @@
 Once it has downloaded it, it will add it to the rest of the already downloaded [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] and hash it, to see if the resulting hash is the same as the hash it should have. If it is, the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] has been successfully completed. If it is not, then it will download the next 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] and so on.
-== What are it's results? ==
+== What are its results? ==
 The best that can happen with ICH is that the first 180KB in the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed ones. If so, only 180KB have to be redownloaded out of the 9.18MB the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is in size.
@@ Line 16: / Line 16: @@
 The worst case sould be when the last 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] are the [[corrupt]]ed bytes. In this case, the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] has to be redownloaded. Anyway, since redownloading the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] would have to be done anyway if ICH had been disabled, this is not a loss at all (except for some little CPU resources).
-== Is it usefull? ==
+== Is it useful? ==
 It is said that it saves up to 50% of the [[corrupt]] downloaded [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]]s on average, which means that out of every 100MB of [[corrupt]]ed data, only 50MB are redownloaded. Which is quite good!

@@ Line 1: / Line 1: @@
 == Description ==
-When a [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is downloaded and results [[corrupt]]ed, [[aMule]] would normally redownload the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] (9.18MB) in order to get the file correctly. ICH (Intelligent [[Corrupt]] Handling) is a workout to avoid redownloading the whole chunk when possible.
+When a [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is downloaded and results [[corrupt]]ed, [[aMule]] would normally redownload the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] (9.28MB) in order to get the file correctly. ICH (Intelligent [[Corrupt]] Handling) is a workout to avoid redownloading the whole chunk when possible.
 == How does it work? ==

@@ Line 5: / Line 5: @@
 == How does it work? ==
-Once a [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is knon to be [[corrupt]], it begins to redownload it. Instead of dropping the whole already-downloaded
+Once a [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] is known to be [[corrupt]], it begins to redownload it. Instead of dropping the whole already-downloaded
 [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]], it keeps it and deletes the first 180KB. It then downloads the first 180KB of that [[FAQ_eD2k-Kademlia#What_is_a_chunk?|chunk]] again.

← Older revision		Revision as of 22:47, 19 October 2004
Line 1:		Line 1:
−	~~While no info is available from ourselves, here is a reliable source to learn about this topic:~~	+	== Description ==

−	~~http://www~~.~~emule~~-~~project~~.~~net/home/perl/help~~.~~cgi~~?l=~~1&topic_id~~=~~589&rm~~=~~show_topic~~	+	When a [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] is downloaded and results corrupted, [[aMule]] would normally redownload the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] (9.18MB) in order to get the file correctly. ICH (Intelligent Corrupt Handling) is a workout to avoid redownloading the whole chunk when possible.
		+
		+	== How does it work? ==
		+
		+	Once a [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] is knon to be corrupt, it beig to redownload it. Instead of dropping the whole already-downloaded
		+	[[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]], it keeps it and deletes the first 180KB. It then downloads the first 180KB of that [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] again.
		+
		+	Once it has downloaded it, it will add it to the rest of the already downloaded [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] and hash it, to see if the resulting hash is the same as the hash it should have. If it is, the [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] has been successfully completed. If it is not, then it will download the next 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] and so on.
		+
		+	== What are it's results? ==
		+
		+	The best that can happen with ICH is that the first 180KB in the [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] are the corrupted ones. If so, only 180KB have to be redownloaded out of the 9.18MB the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] is in size.
		+
		+	The worst case sould be when the last 180KB of the [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] are the corrupted bytes. In this case, the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] has to be redownloaded. Anyway, since redownloading the whole [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]] would have to be done anyway if ICH had been disabled, this is not a loss at all (except for some little CPU resources).
		+
		+	== Is it usefull? ==
		+
		+	It is said that it saves up to 50% of the corrupt downloaded [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]]s on average, which means that out of every 100MB of corrupted data, only 50MB are redownloaded. Which is quite good!
		+
		+	== Is it CPU expensive? ==
		+
		+	Not at all. On any modern CPU, hashing the [[FAQ_eD2k-Kademlia#What_is_a_chunk?\|chunk]]s takes less resources that you would imagine. Since it saves 50% corrputed data in average (and can even save up to 99%) and the hashing process is only done from time to time when necessary, the resources it makes use of are practically null.
		+
		+	Even on old CPUs you should still take into consideration not disabling ICH, since the amount of CPU it takes, compared to the amount of corrupted data it might save, is far enough to keep it active.
		+
		+	To disable it, go to Preferences -> Files -> ICH -> ICH active (disable)
		+
		+	Aditional notes: Take a look at [[AICH\|the AICH documentation]] since [[AICH]] is the evolution of ICH.