The Wabe → Site History

On Bandwidth, Quality, and Perception

Just a couple of thoughts that have struck me over the last week…

• Bandwidth is still a major problem for those of us living outside of universities. While maybe a third of online households in the US are broadband-equipped (Gartner, but certainly skewed positively for its target audience), the rest of us are forced (by money concerns or lack of availability) to access via slow land-line connections. Numerous sites have capped the maximum tolerable size of a page (including graphics) at 60 kilobytes. I try to stay in that range, although I fail miserably in the roadtrip gallery pages.
• Image quality is not an issue. Most people couldn’t tell the difference between a JPEG image compressed at 80% quality and an image compressed at 60% quality. My personal rule of thumb is to compress an image until the artifacts are just visible, then compress a bit more. After all, if you are working with an image for a while, you tend to see flaws that no other human alive will ever notice. Bandwidth costs money, of course.
• So, we know that it’s better to sacrifice photographic quality for bandwidth savings, but what about image formats? I’m a big fan of oddball web comics, but most annoy me to no end by their injudicial choice of format. Comics with large flat areas of color using JPEG (not good) or use too many colors for line art (do we really need to worry about subpixel aliasing?). In the latter case, the savings are substantial: for example, using the web comic Ram (an interesting twist on the teenage superhero angst theme), a naïve compression test using PNG saved on the average 38 kilobytes for each 200 kilobyte image. Compressing the raw data would more than likely be even more efficient. Take a look at Diesel Sweeties for a beautiful example of supporting efficient compression yet allowing access to those browsers that are always a bit behind in their support of modern formats.
• Why should I care? After all, it isn’t my money they’re wasting. But in a sense, it is. Most of these sites (not just web comics, but they tend to be the worst offenders) seem to be constantly begging for money so that they can pay their hosting bills. The hosting services in turn charge a flat rate for unlimited downloads while they themselves pay per byte transferred. So, the amortized cost of hosting is spread over each account on the server. One bandwidth pig hurts everybody.
• The other (and more important) reason is that we insomniacs get mighty frustrated when we want to scan through three years of archives but have to wait a full minute for each bloated graphics-laden page to load. Forget everything your overpaid and underskilled graphics department tells you; minimalism is a win for everybody.

Ahhh, so I’m probably preaching to the choir here, but as a member of the dial-up sans culotte I’m getting more than a little bit ticked off. This is yet another instance of the disturbing problem of usability testing on deployments that are far above a typical user’s configuration.

Last Modified: 2005/04/03 10:02:50 GMT
(Send problems to Rob Menke)
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