AMD/ATI Pixel Clock Patcher

[ToastyX]

(01-02-2020 06:49 PM)treebaard Wrote:  I've tried to search, but am not really getting any relevant results, so I hope people'll forgive me for perhaps asking a question that has already been answered:
I have 2 4k monitors, both with DP 1.2 connectors. Both monitors basically refuse to go above 71hz custom refresh rates, and this struck me as pretty weird. So I had a look at what bandwidth limits DP 1.2 (and HDMI 2.0) have, and I found that for DP 1.2, we're talking about 17.3Gbit. My question is: what effective upper limit should this imply?
This calculator suggests even 4k70 shouldn't be possible (using 8bit color for my TN panel): https://k.kramerav.com/support/bwcalculator.asp ; while 10bit (IPS) should be hopeless. is this correct?

See this post for common pixel clock limits: https://www.monitortests.com/blog/common...ck-limits/

4-lane HBR2 should be able to handle up to 720 MHz pixel clock with 8 bpc, which is enough for 3840x2160 @ 80 Hz with CVT-RB timing ("LCD standard" in CRU would use this). To add a resolution greater than 655.35 MHz in CRU, you have to add it in a DisplayID extension block because EDID detailed resolutions can't go that high.

Now whether the monitor can handle that is another story. Unless you have a monitor that is specifically designed to handle higher refresh rates, most 4K monitors only officially support 60 Hz, and it may skip frames at higher refresh rates if it allows them at all.