I have been using two Dell 2100FP UltraSharp monitors side by side for several years being driven by a ATI Radeon HD 5700 graphics card; one card drives both monitors and both UltraSharp monitors use a DVI connector. One of the UltraSharp monitors finally gave out, probably bad caps. So I bought a Samsung S24B300EL 24" 1080p LED monitor as a replacement and put it next to the UltraSharp. Since the Samsung only had HDMI and VGA inputs and the graphics card only had HDMI and DVI outputs, HDMI was the only way to connect it.
It quickly became apparent that the UltraSharp was much better at rendering sharp edges on text; since I program, having sharp edges on text if very important for eye strain.
I am trying to figure out what it is about the UltraSharp that makes the difference? Is it the connector (DVI vs. HDMI), the dot pitch, or a combination of factors. I suspect it is the dot pitch but that is just from the article.
Please no "I think" or "I suspect" answers.
EDIT
Since I can split a line of text across both monitors, I did this and looked closely, i.e. a few inches away, at the text. On the UltraSharp monitor the text appears without anti-aliasing while on the Samsung, the text appears with anti-aliasing. Also moving the window with the text up and down while looking at the text, on the UltraSharp the text is rock solid from one line of pixels to the next as the text moves, while on the Samsung, you can see the anti-aliasing as it moves up from one line of pixels to the next.
EDIT
I did some more fiddling. The image on the monitor is not edge to edge but has a black border around the image that is not used. So I changed the resolution from 1920 x 1080 (recommended)
to 1776 x 1000
and did the text movement test again. This time the text is rock solid on the Samsung as it moves up and down, just like the UltraSharp. So the aliasing is due to an incorrect screen size.
So based on this and do to the way I asked the question, I will accept an answer.
EDIT
Just found ClearType Text Tuner tool