In a recent post, Dave Shea documented his love/hate relationship with the pixel grid:

Here's the caveat though -- high resolution displays. At 100dpi, ClearType wins out, but we're not going to be stuck here much longer. Give it a few years, let's do this comparison again when 200dpi is standard. I suspect the pixel grid won't matter nearly so much then.

I was somewhat curious about Dave's claim that in "a few years" displays with 200 DPI will be standard fare. So I did some research to document how far we've come in display resolution over the last twenty years.

I used the Tag studios Monitor DPI calculator to arrive at the DPI numbers in the above table. I couldn't quite figure out what the actual displayable area of those early CRT monitors were, so I estimated about 5% non-displayable area based on the diagonal measurement.

Regardless, it's sobering to consider that the resolution of computer displays has increased by less than a factor of two over the last twenty years. Sure, displays have gotten larger-- much larger-- but actual display resolution in terms of pixels per inch has only gone up by a factor of about 1.6.

I can't think of any other piece of computer hardware that has improved so little since 1984.

Some manufacturers do make high resolution displays, but they're far from common, and very few get anywhere close to 200 DPI. Here's one model ViewSonic was demonstrating in 2002:

This 22.2-inch LCD panel being sold by Viewsonic uses the same panel developed and marketed by IBM last year (T220/T221). The difference is that IBM charged nearly $20,000 for its version; Viewsonic plans on selling this one for around $8,000. That's still pretty pricey -- what makes this panel so special?

Try 9.2 million pixels, for one thing. This 16x9 aspect panel has a native resolution of 3840x2400 pixels. That translates to roughly 200 dots per inch. In fact, you have to put your nose up to the screen to really notice the pixels. Scanned topographical maps could be easily read, even down to the smallest typeface. The monitor is targeted towards specialized image processing and CAD applications, and offers a 400:1 contrast ratio. Driving 9.2 megapixels requires a graphics card with twin TMDS transmitters.

High pixel density monitors are far outside the mainstream. The large versions are prohibitively expensive; the small versions can't justify their price premium over the lower-resolution competition with larger physical size. It's telling that today, in 2007, the Apple store doesn't even sell a single standalone LCD offering over 100 DPI. Nor can I find a single high resolution LCD of any type on newegg. I have no doubt that if I had $10,000 burning a hole in my pocket, I could buy a 200 DPI display somewhere, but at consumer prices and through consumer outlets, high resolution displays simply don't exist.

Most of the time, you see high resolution display options on laptops, where the notebook form factor physically precludes the display from getting any larger. Manufacturers are forced to pack more and more pixels into a LCD panel of a fixed size:

When I purchased my notebook I had a choice of three monitor resolutions - the standard 1200 x 800, 1680 x 1050, and 1920 x 1200. The diagonal screen size is 15.4" giving me the three corresponding pixel densities of 98, 129, and a whopping 147 ppi!

It's hard to see this choice of display resolutions as anything other than a side-effect of laptop size restrictions. If notebook vendors could somehow fit a folding 30" LCD panel into a laptop, they absolutely would. But even at 147 DPI, we're only halfway to our goal. To reach 200 DPI, that same 15.4" laptop display would have to pack in 2560 x 1600 pixels. Imagine a 30" Apple Cinema HD display shrunken by half, and you'll get the idea.

Short of some kind of miraculous technological breakthrough, I can't see computer displays reaching 200 DPI in "a few years". It's unlikely we'll even get there in ten years. I'd love to be proven wrong, but all the evidence of history-- not to mention typical consumer "bigger is better" behavior-- is overwhelming.