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[GNUnet-SVN] r1985 - GNUnet-docs/WWW
From: |
grothoff |
Subject: |
[GNUnet-SVN] r1985 - GNUnet-docs/WWW |
Date: |
Sat, 27 Aug 2005 23:39:46 -0700 (PDT) |
Author: grothoff
Date: 2005-08-27 23:39:46 -0700 (Sat, 27 Aug 2005)
New Revision: 1985
Modified:
GNUnet-docs/WWW/faq.php3
Log:
update
Modified: GNUnet-docs/WWW/faq.php3
===================================================================
--- GNUnet-docs/WWW/faq.php3 2005-08-28 04:08:06 UTC (rev 1984)
+++ GNUnet-docs/WWW/faq.php3 2005-08-28 06:39:46 UTC (rev 1985)
@@ -47,6 +47,7 @@
W("GNUnet is free software, available under the %s (GPL).",
extlink_("http://www.gnu.org/copyleft/gpl.html",
"GNU Public License"));
+W("You are free to run, distribute or modify the code under the terms stated
in that license.");
W("We are a part of the %s.",
extlink_("http://www.gnu.org/","GNU project"));
EP();
@@ -367,45 +368,22 @@
W("The answer to this is, that encryption is incredibly fast.");
W("GNUnet uses mostly AES-256, a very fast and secure cipher.");
W("What really often makes anonymous file-sharing slow are artificial delays
that were introduced to make timing analysis hard and to group messages into
larger packets.");
-W("The best illustration for this is the following timing results obtained by
inserting and downloading a 3 MB binary from the local host (no real networking
involved, only loopback).");
-W("Insertion takes (on a Celeron 667, 400 MB RAM):");
-
-P();
-PRE("real 3m38.954s\n" .
- "user 0m2.450s\n" .
- "sys 0m0.410s");
-P();
-W("For the download, it takes:");
-P();
-PRE("real 0m13.796s\n" .
- "user 0m2.150s\n" .
- "sys 0m0.660s");
-
-P();
-W("As you can see, the <em>user</em> CPU usage (how much is actually used) is
miniscule compared to the <em>real</em> time that it took to download the
file.");
-W("The real time is longer because the harddrive could not perform the random
accesses to the GNUnet databases any faster.");
-P();
-W("GNUnet thus uses CPU and network resources fairly responsibly.");
-W("The only thing that GNUnet “wastes” is time, in some sense, it
sits idle.");
W("The reason is, that this makes it harder to correlate actions.");
W("GNUnet must wait for enough traffic from other peers to make it plausible
that the traffic did not originate from the local peer.");
W("Larger delays also allow for more reordering of messages by the individual
peer.");
-W("GNUnet peers try to maximize bandwidth utility by reordering messages.");
W("By allowing peers to delay messages, it is easier for them to build more
efficient messages.");
-W("Once the load in GNUnet goes up, GNUnet will increase its actual
utilization of resources up to the maximum specified by the user (see
gnunetd.conf).");
-W("Thus, in some sense, GNUnet is slow but efficient.");
-
P();
-
-W("The GNUnet developers are trying to make the perceived response times
faster; yet, there is not much hope that the response times will get close to
typical response times from other applications like the WWW.");
-W("Due to improvements in the code, the numbers quoted above may not always
reflect the actual performance of the current version.");
-
+W("The primary cause of CPU consumption in the current implementation are
algorithms for message scheduling.");
+W("GNUnet peers try to maximize bandwidth utility by reordering messages.");
+W("Also performing downloads in parallel can cause some significant accounting
issues.");
+W("Many datastructures used currently are simple lists that take time linear
to their size to operate on.");
+W("For local indexing operations the current release is typically pushing the
limits of both the CPU and the harddrive.");
P();
-
-W("Theoretically, it is possible that a download via GNUnet is even faster
than a download from a crowded webserver or a single dialup user, but how
likely this is depends in practice on the content -- and we neither promise nor
really expect to achieve this level of performance.");
+W("We expect to use smarter, faster datastructures in the future to reduce CPU
consumption.");
+W("The GNUnet developers are always trying to improve performance; yet, there
is not much hope that performance will ever get close to typical response times
from other applications like the WWW.");
+W("Theoretically, it is possible that a download via GNUnet is even faster
than a download from a crowded webserver or a single dialup user, but how
likely this is depends in practice on how the content is spread throughout the
network -- and we neither promise nor really expect to achieve this level of
performance.");
W("While peer-to-peer networks can theoretically provide better performance
than dedicated servers, their true strength lies in the possibility of being
anarchistic: low administrative overhead, anonymity, no single point of
failure.");
W("Complete decentralization is very costly and we should thus not expect to
outperform the centralized solution, especially not if we also want
anonymity.");
-
EP();
ANCHOR("lastblocks"); H3("Why is downloading the last few blocks so slow?");
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