[thelist] Really dumb question...

[Jackson Yee]

That depends on the bandwidth of the pipe, whether the images are coming from
multiple servers or the same server, and how the connections are made.  Many
web designers used to split images up so that modem viewers could
incrementally see how the page was laid out before the entire graphic was
downloaded - along the same ideas as interlaced GIFs and adding width and
height attributes to every image.  However, broadband connections have
lessened the need for progressive displays, and have also allowed multimedia
formats such as streaming or Flash to become practical.  Splitting images up
also creates more work for the developer, as you will have to make sure that
the image fragments are properly aligned and positioned on every browser,
usually leading to a lot of code with <table>'s

>From a purely developer's point of view though, separating an image into
smaller images adds overhead to the file sizes because each image will require
a separate file header.  The more influential matter though, is that each
image download request requires a separate HTTP connection, which requires
time and effort on both the client's part and the server's part to setup.  You
may also be limited by the number of simultaneous HTTP connections that a
particular machine supports, which is four for HTTP 1.0 and two for HTTP 1.1
on many Windows machines.  If you split an 80kB image into eight different
10kB sections, it will probably download slower than having one single large
image due to the above reasons.

[Details for number of connections]
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q183110

My preference has always been to keep the image as a single file rather than
separating it into multiple files unless you have good reasons to do so.  You
know your audience and your intent for the page though, so if it works for
you, go right on ahead.

Regards,
Jackson Yee
jyee at vt.edu
http://www.jacksonyee.com/

----- Original Message -----
From: "Ken Kogler" <ken.kogler at cph.org>
To: <thelist at lists.evolt.org>
Sent: Monday, July 08, 2002 15:14
Subject: RE: [thelist] Really dumb question...


> >>... two 10Kb graphics would download twice as fast as one
> >> 10Kb graphic, no?
>
> > ROTFL, but valid to the subject of this thread.
>
> D'OH! *smacks head against wall*
>
> I meant two 5Kb graphics vs. one 10Kb graphic.
>
> That's what I get for typing and talking on the phone at the same time...
> I'm going to go see if my doctor con do a foot-ectomy on my mouth... later!