• Hardware

  • Intel confirmed no dithering on Intel arc a770

moonpie i meant: if someone has a other gpu, he could test it by disabling it.

And if the gpu is the issue, using intel arc could solve it.

    autobot

    we could also disable the gpu like this:

    https://superuser.com/a/210381

    The environment variable LIBGL_ALWAYS_SOFTWARE=1 switches Mesa to use CPU for calculations. The graphics card continues to function normally and is managed by its driver. When I enable software rendering, the image quality seems a bit nicer. Previously, I noticed that colors change between CPU and GPU rendering, which might trigger the FRC module on my monitor. So, I'm currently using only software rendering, but I can still manage the graphics card through the driver (I have it set to 6-bit). I think for cards where the driver enables dithering, software rendering won't fix the issue.

    Below is the system information for the software rendering mode:

    $ inxi -G
Graphics:
Device-1: Intel DG2 [Arc A770] driver: i915 v: kernel
Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X:
loaded: modesetting unloaded: fbdev,vesa dri: swrast gpu: i915
resolution: 1920x1080~60Hz
API: EGL v: 1.5 drivers: iris,swrast platforms: gbm,x11,surfaceless,device 
API: OpenGL v: 4.6 compat-v: 4.5 vendor: mesa v: N/A renderer: llvmpipe (LLVM 18.1.3 256 bits)
API: Vulkan v: 1.3.275 drivers: N/A surfaces: xcb,xlib

$ lsmod | grep i915
i915                 4329472  5
drm_buddy              20480  2 xe,i915
ttm                   106496  3 drm_ttm_helper,xe,i915
drm_display_helper    253952  2 xe,i915
cec                    94208  2 xe,i915
i2c_algo_bit           16384  2 xe,i915
video                  73728  2 xe,i915

    llvmpipe (LLVM 18.1.3 256 bits)is the CPU (software) render.

    The lsmod command indicates that the video driver is loaded.

    To “disable” the video card, you need to blacklist its driver. In this case, Mesa will also switch to software rendering, but the video card driver won't be loaded.

        WhisperingWind

        I've blacklisted the i915 driver.

        inxi -G

        Graphics:

        Device-1: Intel driver: N/A

        Display: x11 server: X.Org v: 1.21.1.4 driver: X: loaded: modesetting

        unloaded: fbdev,vesa gpu: N/A resolution: 1920x1080\~60Hz

        OpenGL: renderer: llvmpipe (LLVM 15.0.7 256 bits)

        v: 4.5 Mesa 23.2.1-1ubuntu3.1\~22.04.2

        echo $XDG_CURRENT_DESKTOP

        XFCE

        "enable display compositing" = off

        System is less comfortable than

        inxi -G

        Graphics: Card: Intel Device 46d2

               Display Server: x11 (X.Org 1.20.4 )

       drivers: fbdev (unloaded: modesetting,vesa)

       Resolution: 1920x1080@77.00hz

       OpenGL: renderer: llvmpipe (LLVM 8.0, 256 bits)

       version: 3.3 Mesa 19.0.8

        ubuntu 18.04(zorin 15 lite)

        echo $XDG_CURRENT_DESKTOP

        XFCE

        "enable display compositing" = off

        Maybe some other small differences between. i"m not sure.

            autobot

            This sounds intriguing! I will install Ubuntu 18.04 and try to figure out which system components might differ.

                autobot

                It's like gold mining: the more sand we sift through, the better our chances of finding something valuable. 🙂

                  I tried latest ubuntu with my Intel iGPU 12900K and it was bad, dithering almost instant feeling. Tried with latest Fedora, looks like no issues, i'm still testing.

                    madmozg

                    I tried latest ubuntu with my Intel iGPU 12900K and it was bad, dithering almost instant feeling

                    Try running the command

                    sudo cat /sys/kernel/debug/dri/1/i915_display_info

                    in the terminal. The command will output a lot of data, but among it, there should be information about the presence of dithering

                    dither=true|false

                    1 is the device number, which can be obtained through

                    inxi -G

                    But if there is only one video card, it should be 1.

                      moonpie I will try ubuntu. I just loaded to Fedora with my Nvidia 3070 Super, but looks like fedora is in hybrid mode, I can't find any active resolution in i915 file. So currently I have hdmi connected through nvidia gpu and it still not dithering. I'm trying to switch graphics with this tool I found https://github.com/bayasdev/envycontrol

                        2 months later

                        WhisperingWind i5-12450H , Intel UHD Graphics Xe (driver v. 31.0.101.5537), Windows 11 23H2, 8-bit monitor.

                        Hello WW, happy new year!

                        Could you pls share extra settings you have in mini-PC: PC model name, ram used? You also mention, it doesnt have "true" HDMI, which connectin you use for your monitor (and whats your monitor)?

                            simplex

                            Hello simplex, happy new year!

                            I have this mini-PC: https://www.tecno-mobile.com/pc-tablets/product-detail/product/mega-mini-m1

                            Processor: i5-12450H, Graphics: Intel UHD 48EU (Xe arch), RAM: 2 × DDR4 3200 8 GB Lexar LD4S08G32C22ST. It was connected via type-c (DP) and HDMI. The display used was Sony TV (8+FRC), BenQ BL2711U (8+FRC) and BenQ GL2450 (6+FRC).

                            This mini PC has a two true HDMI ports. However, there are two Type-C ports that operate in DP mode. When using a true 8-bit monitor, my eyes felt comfortable.

                            Cons:

                            • It has a VERY noisy cooling system (IMHO).
                            • the processor receives about 38.6 watts maximum (I saw this figure in some reviews), which prevents the CPU from performing at 100% of its capabilities.

                            Pros:

                            • The absence of dithering in Linux/Windows (tested only on Windows 11).
                            • The ability to switch to 6-bit video output mode in both Windows 11 and Linux without enabling dithering. I am visiting relatives, and I brought this mini-PC with me. I'm currently testing it with one of my relatives' monitors, the BenQ BL2420PT (6bit+FRC), in 6-bit video output mode on Windows 11 23H2. For now, this is the only way for me to work with this monitor, as I couldn't switch my relatives' PC (i5-12400, UHD 730) to 6-bit mode without enabling dithering, just like my ARC A770. Later, I will compare it with Ubuntu Linux on the same monitor in 6-bit video output mode.

                                WhisperingWind Processor: i5-12450H, Graphics: Intel UHD 48EU (Xe arch), RAM: 2 × DDR4 3200 8 GB Lexar LD4S08G32C22ST

                                I currently use mini-PC: i7 13700h + DDR5 4800 mhz KVR48S40BD8K2-64 + Iris XE 96UE with benq bl2420z (via HDMI to DVI cable). When I switched memory to KF556S40IB-16, I got strain. I also got strain with mini-PC 8845hz + 780m even with KVR48S40BD8K2-64 modules, but a little lower level comparing to default 5600 mhz modules. After experiments with registers, we with SunnyCove switch off all dithering settings in AMD, but 780m still strain 🙁

                                My hope was, Intel 12..14 gen CPUs works better with DDR5 gen ram, but your config shows it can be perfectly with DDR4 3200 without issues.

                                To be honest, 13700h + IRIS XE good with 4800 mhz DDR5 which have standart, not OC JEDEC timings (CL40). Lowering 5600 to 4800 timings with two different RAMs, didnt helps (only RAM with 4800 CL40 max is good). Your DDR4 also seems to have standart 3200 mhz timings (CL22).

                                The joke is, I tested laptop with same IRIS XE (13900h) but with LPDDR4 with win11 preinstalled, I play with it in 30 min and after leaving shop, got strain. So I dont really know, does lpddr4 matters in this case, or only screen pixel inversion/FRC (keeping in mind, IRIS XE is safe)

                                  WhisperingWind my relatives' PC (i5-12400, UHD 730)

                                  Could you please check, whats motherboard they use (incl BIOS ver), which DDR4 model names (freq, timings)…? 12400 is okay for your taste, does they use iGPU only?

                                      dev