[Tutor] OT: need computer advice from wise Tutors

Alan Gauld alan.gauld at btinternet.com
Tue Jun 29 10:06:46 CEST 2010

"Richard D. Moores" <rdmoores at gmail.com> wrote

>> You log into Gmail and your browser downloads the Gmail page;
> Yes, of course. But I'm always logged into Gmail.

But it is stiill continually downloading. The same applies to a
desktop client, if you leave it running it can continually poll the
server, just like gmail.

> With Eudora I would have to manually *download* new email
> to see what was new (as I recall, there was a way to set
> Eudora to check for new mail at an interval I could set

But nobody with an always-on conection would sensibly do that, the
tool polls the server - in my case every 15 minutes, but it could
be more often; at work its every minute.

> That's what I meant by "my mail is just always THERE", and because 
> you
> know the difference between OE and Gmail you knew what I meant,

But its exactly wrong because in gmail your mail is never there.
It has to be fetched each and every time you read it. In OE/Eudora/TB
it is really there on your PC. You can read it even when offline.
Web mail is fantastically inefficient and a huge waste of bandwidth.

One of the big problems with the move towards "Cloud Computing"
is the massive amount of extra bandwidth required - who is going to
pay for it? The telcos can't affiord to keep on giving unlimited bits 
everyone, there will need to be new charging models introduced to
make the whole thing viable. This is a very big and important issue
and as Steven says we as programmers need to understand the wider
implications of the programming solutions we build.

> Of course. Just like anything else which has to get from a Gmail
> server to me. If text, that's a small fraction of a second for me. 
> So
> small that it appears to be instantaneous.  If there are images, 
> it's
> still a small fraction of a second, and images are usually there by
> the time I can scroll down to them.

You must have very fast broadband! Images general take several
seconds over my 2M (nominally 8M) connection (on a good day,
often it slows to under 1M if the neighbours are watching IP TV...)

> Sure, but I have broadband access, as do many.

But that is still a shared resource and even if you have high
speed ADSL+ (20M+) it is still a performance bottleneck that
you need to be conscious of.

I know this discussion started as a flippant comment but it does bring
to light some very serious challenges for programmers. We all need to 
aware of the bottlenecks ion our designs and currently network
bandwidth (and latency but that's another debate) is the biggest
bottleneck for many applications. (And its nice to see an OT thread
come back on topic! :-)

Alan Gauld
Author of the Learn to Program web site

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