• Hardware

  • Intel confirmed no dithering on Intel arc a770

When I enabled Auto Color Management (by default, ACM was disabled), I got the following entry in the log:

Address = 603c000000 RegisterAddress = 70030 Address + RegisterAddress = 603c070030 RegisterValue = 4000110 RegisterDataFromDB = 0 RegisterMaskFromDB = 1c NewRegisterValue = 4000100
We should update the register with the value 'NewRegisterValue' because it is not equal to 'RegisterValue'. The updating was successful.

The register value 0x4000110 in binary representation is 0100000000000000000100010000. The fifth bit is set to 1. According to the ditherig database, this is Spatial dithering. Its value in the database is 0x00000010 (00000000000000000000000000010000), i.e., the very same fifth bit.

14 days later

reaganry

It might depend on the vendor, but my Asrock ARC A770 doesn't dither by default in Windows 11 (if ACM is turned off).

    reaganry No good user reports about intel arc yet?

    my 128EU Arc iGPU was bad. Not sure, GPU or screen (or both) issue

        simplex when you turn of the GPU(i.e. choose basic vga driver in windows) does it solve/improve that?

            autobot does it solve/improve that

            nope

            Even safe win10 1809 build didn't solve that. tbh laptop's screen could be reason but I sold laptop half-year ago, only now I understood issue could be in:

            1) screen (noticable pixel-inversion especially in all new screens I tested)

            2) motherboard/CPU/GPU (some users noted swithing motherboard solve eye-strain, some users told only CPU (amd 5600g to 5700g) switch give extra eye-strain, and I myself got strain using rtx20 and newer series over gtx10 line keeping exact same PC components)

                I dont think an OS will do dither at software level, I only know some monitors will do dither at hardware level which hurt eyes.

                simplex one possible way to do the testing is use a a safe live usb distro, for example lubuntu 18.04, and try at friends with pcs etc until finding some safe hardware.

                It doesnt use the gpu driver though, but it's much better solving it starting from safe hardware/monitor.

                    autobot starting from safe hardware/monitor

                    I still haven't found a safe business laptop (16-18" with 300nit screen and 72% NTSC, not old amd/intel with iGPU, 16/32gb memory, 60+ watt battery)

                      I have a hypothesis regarding Ubuntu 18: the display might feel easier on the eyes because some new graphics cards aren't supported, resulting in an image that's less straining. If that's the case, we could blacklist the necessary kernel modules to achieve the same effect in newer versions of the OS.

                        autobot

                        I don't think it's specifically about the distribution itself. It's more about a set of useful hacks and configurations that might work for certain hardware.

                          WhisperingWind we could also disable the gpu like this:

                          https://superuser.com/a/210381

                          It's easy to just try it on a given system and see if it solve the issue.

                          And if this solves the issue and we know that using intel Arc also is dithering and eye strain free, that's easy to buy an Arc card if a gpu is needed.

                              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.

                                    dev