Custom Resolution Utility (CRU)

[ToastyX]

(01-11-2016 07:35 AM)Larwood Wrote:  I had my 60 Hz monitor overclocked to 75 Hz just fine over a straight HDMI cable. Today I changed it to be connected via a mini displayport to HDMI adapter, but when I try to add new refresh rates it doesn't work over 71 Hz. As you can see from my screenshot the resolution simply isn't recognised by Windows.

Previously when it was straight HDMI I could add any refresh rate I liked and it would appear on the list whether the monitor would actually support it or not. Am I missing something? I'm using the exact same settings as I was before.

You're running into pixel clock limits. The main post has more information.