I have a LG 27ML600M monitor that supports 75hz but when I set Mac OS to 75hz in the display settings it looks blurry. If I set it back to 60hz it looks normal. Any ideas on why this is happening? It is a 2010 Mac Pro with the AMD 5770 card.
Mac Pro
That display appears to be a 1920 by 1080 display with two HDMI inputs, no Displayport.
The cables you want for HDMI-only Monitors (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:
"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--
"Ultra High Speed HDMI cable" or that + "48G"
Cables with No Certification tags are good for your standard 720p TV set, and not much more.
It appears that this card is limited to 60hz at 1080p. If I wanted 75hz I have to lower the resolution. The same behavior was seen in bootcamp, which confirms it.
I tried different cables but that didn't work. Using the same cable with my other windows PC's show that they support 75hz but aren't blurry. I think it's something with my Mac.
the 5770 has a DVI-I output and two Mini DisplayPort outputs. How are you connecting to an HDMI-only display?
What ports and what cables on your Windows machine are you using?
I am using a DVI to HDMI cable that does 75hz on my windows pc but not on my mac. Using the exact same cable on my windows pc works just fine.
Mac Pro Blurry output on 75hz.
