Max OS X: White saturation is terrible [duplicate]

I bought a new LCD-Monitor: Acer S235HLBbmii. I had Windows 8 until today. The colors with Windows (and this monitor) were very good. All tests on this website are very good: http://www.lagom.nl/lcd-test/

I connected my new Apple Mac Mini (2012, quadcore 2.3 GHz) to this display. The colors are very terrible.

I tried macOS color calibration, different modes/settings in the OSD menu and the Windows 7 Color Profile (ICM) from the Acer website.

This test especially is just worst: http://www.lagom.nl/lcd-test/white.php

It shows me the first block (200). I can't see any other. So you can imagine that bright pictures with a lot of white amount looks very bad.

Switching back to Windows 8 isn't considerable so I need to get this fixed.

Here is a link: https://www.dropbox.com/s/pf667jgx2idz4sl/Foto%2005.02.13%2020%2012%2043.jpg

P.S.: I downloaded and installed all updates. Monitor is connected via HDMI 1.4 Cable (good quality) and also i tried the old DVI to HDMI-Cable (which powered the display under windows) with the adapter that was shipped. Not a single improvment.

P.S.S.: Tested video out on my 27 inch Yamakasi, the white saturation is near the same. It's crap. It's oviously a software fault. What can i do to fix this? :-(

Any help is very appreciated!

I FIXED IT! The HDMI out of the mac mini is very poor. I connected the via mini displayport and all went fine.

(mini displayport -> dvi -> hdmi, crazy but works better then HDMI <> HDMI).