Custom Resolution Utility (CRU)

[calamaritrunks]

Hey Toasty, thanks for CRU. I've been using it for a while now to great effect. I've now however, run into a little trouble. I was running an AMD HD6970 miniDP to HDMI adapter to a Samsung UN6950 TV at 1920x1080p 120fps with CVT timings and it was working great. I "upgraded" to an R9 380X yesterday and haven't been able to get that same resolution working, on either of the HDMI1.4 or DP1.2 outputs from the card to either of the HDMI1.4 or HDMI2.0 inputs on the TV.

Now whenever I set up that 1080p120fps custom resolution, the bottom third of my screen gets artifacted and frozen on a strobing effect, while the top two thirds are heavily artifacted but appear at the proper 1080p with 120fps resolution. Interestingly, this is the same effect I get when trying to run that resolution with anything less than CVT timings i.e.CVT-RB/RB2 on my old otherwise working setup or if trying to run with CVT timings and 10bp color.

A bit of testing reveals that now, the AMD driver refuses to awknowledge anything above 297mhz TDMS clocks on HDMI1.4 input to TV. Custom resolutions with these clocks don't show up as options in "List All Modes" or "Monitor Refresh Rate". And CVT (or any other timings) doesn't work on HDMI 2 input. At 60hz or below things work as expected. I can get 4k30fps on HDMI1.4 input to TV from either output, and 4k60FPS on HDMI2 from the DP1.2 with adapter. So all in all, I know that 1080p120FPS works on my TV, I know I can get way more than the necessary bandwidth for it even with this new card, and I know the cables and everything work.

I suspect the solution would be to get 1080p120fps working on HDMI1.4 input which is what I had before from my 6970 (or my 8970M laptop). But I haven't found a way to bypass that 297mhz limit even though I using the DP1.2 output so it shouldn't even enforce it as far as I know.

I'd appreciate any insight you could offer. Thanks!