Hi all!
For some reason I just can’t get my 4k TV (which I’m using as a monitor) to run 4k@60Hz in linux, using my iGPU. The TV has only HDMI inputs - I have active DP 1.2 to HDMI 2.0 adapter which works fine (used it a lot with my old GPU - GTX 970 in a hackintosh build, also tested on GTX 1070 on linux and windows).
In windows, can run run 4k@60Hz using iGPU, but only after I add a custom resolution using Intel’s drivers. I’ve tried to do the same undex linux, but that’s where I’ve failed. Whatever I try, I just get “No signal” on the TV.
First, I’ve tried adding a custom mode for the regular 3840x2160@60Hz signal:
cvt 3840 2160 60
# 3840x2160 59.98 Hz (CVT 8.29M9) hsync: 134.18 kHz; pclk: 712.75 MHz
Modeline "3840x2160_60.00"  712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
xrandr --newmode "3840x2160_60.00NR" 712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
xrandr --addmode DP-1 3840x2160_60.00NR
xrandr --output DP-1 --mode 3840x2160_60.00NR
xrandr: Configure crtc 0 failed
That just fails with Configure crtc 0 failed
error message. After some googling, I’ve concluded that integrated GPU does not have enough bandwidth to run full 4k@60Hz signal. Not sure if that’s true or not, but I believe I’ve got the similar error under windows. After that I’ve tried adding a new mode using reduced blanking. This works fine under windows, but not under linux. Here’s what I’ve done:
cvt -r 3840 2160 60
# 3840x2160 59.97 Hz (CVT 8.29M9-R) hsync: 133.25 kHz; pclk: 533.00 MHz
Modeline "3840x2160R"  533.00  3840 3888 3920 4000  2160 2163 2168 2222 +hsync -vsync
export X="3840x2160_60.00R"; xrandr --newmode $X 533.000000 3840 3880 3920 4000 2160 2165 2175 2222 +HSync -VSync; xrandr --addmode DP-1 $X; xrandr --output DP-1 --mode $X
After running the commands above, all I get is “No signal” error on the TV. I’ve compared timings I got from cvt and Intel driver, and they are different. They also use different terminology. I’ve tried a lot of variations to the timings I’ve got from cvt
, but non have worked. I’ve also tried what I think works with Intel drivers under windows, but it also didn’t work.
I’m not sure how to proceed or where to look, any suggestions?