Custom Resolution Utility (CRU)

[falkentyne]

ToastyX,

is it possible (or even feasible) to make a patch to bypass the displayport limits, or at least to extend the pixel clock range for 8 bits per channel color, or is this not possible?

The AMD Drivers automatically switch to 6 bits per channel color depth when 359.99 (or 360.00 MHz) pixel clock bandwidth is exceeded, and any clock above 480.00 MHz isn't even recognized by the driver (the R9 290X has a DP 1.2 port so it should theoretically be capable of 600+ MHz). I assume this is because the XL2720Z/XL2420Z are DP 1.1a and the drivers enforce limits perfectly?

This issue of course doesn't happen over DVI (you can't even choose the bits per channel depth over dvi).

I was able to enforce 120hz, with a Vertical total tweak in the internal max range (1497-1502 send a scaler resolution signal of 1440 vertical for reduced strobe crosstalk, at least according to the factory service menu) by using the lowest horizontal total and vertical total possible before CRU would turn red for the HT value (2001 HT, bare minimum). I used a VT of 1499, any higher and I'm over 360 mhz. Any value below VT 1497 is "Out of Range!". for 359.94 MHz and 8 bits per channel color, but no such luck at 125hz (driver forces 6 bpc).