Neil Harris wrote:
Now, if a connection was being limited by TCP startup
alone,
this means that data would be delivered somewhere between four
and ten times faster, and in particular that page-rendering
would be able to start four to ten times as quickly. In
practice, this is not the sole factor involved, so observed
gains will not be as great as this, but they will certainly be
very noticeable by users.
I disagree. There might be other (political?) arguments for
different datacenters, but ping times in Western Europe is not one
of them. You are talking about possible gains of .2 seconds or
less here. When "Wikipedia is slow", it is because each HTTP
request takes 5 or 6 seconds or more instead of 2 seconds.
According to Alexa, average response times for some websites are:
fast:
0.7 seconds
http://www.alexa.com/data/details/?url=mit.edu
0.8 seconds
http://www.alexa.com/data/details/?url=google.com
1.0 seconds
http://www.alexa.com/data/details/?url=susning.nu
1.1 seconds
http://www.alexa.com/data/details/?url=tu-berlin.de
1.1 seconds
http://www.alexa.com/data/details/?url=stanford.edu
average:
1.6 seconds
http://www.alexa.com/data/details/?url=yahoo.com
1.9 seconds
http://www.alexa.com/data/details/?url=wikipedia.org
2.0 seconds
http://www.alexa.com/data/details/?url=slashdot.org
2.0 seconds
http://www.alexa.com/data/details/?url=gutenberg.org
2.0 seconds
http://www.alexa.com/data/details/?url=heise.de
slow:
2.8 seconds
http://www.alexa.com/data/details/?url=amazon.com
3.1 seconds
http://www.alexa.com/data/details/?url=cnn.com
3.1 seconds
http://www.alexa.com/data/details/?url=wired.com
3.4 seconds
http://www.alexa.com/data/details/?url=nytimes.com
tired:
4.8 seconds
http://www.alexa.com/data/details/?url=techreview.com
5.6 seconds
http://www.alexa.com/data/details/?url=wikimedia.org
Note that TU-Berlin and Susning are in Europe, while Stanford and
Google are next door to Alexa. Nobody is unhappy with the
performance of Slashdot or Wikipedia as long as the response time
is around 2 seconds. MIT Technology Review has a remarkably slow
website for carrying the prestigeous MIT brand. If Wikimedia's
(
commons.wikimedia.org) average response time is actually 5.6
seconds, people should be complaining. If ping times were to
blame,
Wikimedia.org would be on the Moon.
--
Lars Aronsson (lars(a)aronsson.se)
Aronsson Datateknik -
http://aronsson.se