This post will be a bit different from my others. It's less focused on enterprise IT work and more on personal computing.
For Christmas, I got a Mac Mini. This is my first foray into Apple computing instead of Microsoft computing. I am learning, slowly but surely.
I plugged my Mac into my "monitor," a Samsung SyncMaster P2770HD. I left my Windows PC plugged into the DVI input, and plugged the Mac into the HDMI.
I was dismayed to have very poor video quality. The color was off, and the video quality was very jagged and unsatisfactory. Adjusting settings on the Mac and messing with the resolution effected no positive change. As a work around, I used the Mac's HDMI to DVI adapter, but that wasn't my desired configuration. I wanted to rely on the TV/monitor speakers.
Some searching online tipped me off to the culprit. (I have misplaced the link as to where I got the good info, I believe it was on Apple support forums.)
The fix was to "label" the HDMI input as being a PC. I thought these labels were merely for display purposes to help remind you what was on each input, but clearly it does more than that and adjusts the quality. Once I performed these steps, I was getting the quality video I expected.
On the TV, the command changes can be found at Menu | Input | Edit Name | HDMI. Then you select PC and you have good video output from the Mac to the Samsung.