Two identical external monitors, one through HDMI another VGA. Text on VGA looks blurry

VGA is analog. HDMI is digital. Meaning: the digital output of your computer is converted to the analog VGA signal. The analog VGA signal is converted back to a digital signal by your monitor. These conversions depend on the quality of the involved cable, connectors and especially the analog/digital converter components within your graphics card and the monitor. It can be very good, but never perfect. Some data is always lost/changed. At low resolution, this difference is not notable. At higher resolutions, it is. And with the analog use case being not very common nowadays, you can expect vendors to use cheaper/worse A/D converters for current hardware, not better ones. See also: http://www.brighthub.com/computing/hardware/articles/23769.aspx

Each and every VGA flat-panel display has an "Auto" button. It automatically adjusts the interpretation of the analog signal to achieve a (more or less) pixel-perfect mapping.

Activate this function when the outer edges of the image displayed are clearly defined (nothing black) and you have text visible.

Still, 1080p is in the upper regions of what's possible (at all) with VGA and many devices nowadays have lowish-quality VGA output.

Basically, HDMI is digital and VGA is analogue.

There are a few solutions:

1) Buy a docking station which provides access to 2x HDMI or 1x HDMI + 1x DVI.

2) Use an on-board DVI instead of the VGA.

3) Buy a HDMI -> VGA converter. The 1st VGA will no longer seem blurry in comparison with the HDMI.