Intel HD Graphics 4600 and Black Levels - HDMI vs DVI

Late last year I built a new Windows 8.1 computer with an Intel i7-4771 processor installed on a Gigabyte GA-H87-D3H motherboard with 16 GB of RAM.

 

I originally had a dual-monitor set-up with a 27" Viewsonic VX2770Smh-LED monitor connected to the HDMI port and a 23" LG Flatron IPS236 connected to the DVI port.  Please note which monitor is connected to which port.

When I compared the black levels and colors between the two monitors I was really impressed with those on the LG monitor (connected to the DVI port) but really disappointed with the black levels and colors displayed on the Viewsonic (connected to the HDMI port).  Images and videos looked more washed out on the Viewsonic and the black levels were very noticeably different.  I spent a lot of time adjusting settings on the Viewsonic monitor itself and in the Intel HD Graphics Control Panel software.  I was never able to get satisfying results.  My first thought (turns out incorrect as explained below) was that the Viewsonic monitor was simply not able to produce satisfying black levels and colors.

I did some research online about the Intel HD Graphics 4600 GPU and was surprised to find that others had experienced problems with black levels on the HDMI port vs those produced by the DVI port.  I decided to switch the connections to the monitors.

DVI  Black Levels vs HDMI Black Levels - Intel 4600 GPU

 

This was the problem!!  Now that the Viewsonic VX2770Smh-LED monitor was connected to the DVI port, it was displaying superior black levels and colors compared to the LG IPS236 monitor connected to the HDMI port.  I am quite surprised by this and would have expected that the HDMI port and the DVI port would have produced the same quality image.  Although I have not tested it out yet, based on information I quickly read on the internet, I am suspicious that the VGA port would also produce better black levels than the HDMI port (but this is only speculation and I have not verified this suspicion).

Intel HD Graphics 4600 GPU - Monitor Connection Advice

For single-monitor setups: Connect your monitor to the DVI port and not the HDMI port of the Intel 4600 GPU.

For dual-monitor setups: Connect your primary monitor to the DVI port and your secondary monitor to the HDMI port.

One caveat to remember is that only the HDMI port carries audio information.  So if your monitor has speakers you are planning on using then this may effect your decision.