[HELP] Overclocking with HP Z23i using Displayport & GTX 970

[kangjooe]

Hello, i need some help overclocking with my display HP Z23i with displayport connection.

usually i can overclock up to 78hz @ 1080p with custom timing, BUT i notice that timing is all below 165 pixel clock. when i try higher Hz like 79 or 80, the pixel clock is up above 165 pixel clock, and it all goes blank.

i read that display port can do up to 300 pixel clock or so (clearly far above 165 pixel clock limit by hdmi / dvi AFAIK). when i check my monitor status via Aida64, it shows that my monitor capable to run @ 200 pixel clock max, so realistically i can go to 190 for example without problem right? so is there anything wrong with my setup?

spec:
- monitor HP Z23i using displayport (with converter mini-displayport to displayport)
- Palit GTX 970 Jetstream (mini-displayport)
- Windows 8.1 x64

on the attachment is SS of my Hp Z23i info from aida, maybe that will help.

so the question is, why can't i go above 165 pixel clock while i'm already using displayport? i want to try for 80hz or a little above.

Thanks before