Flicker-Free Linux?

diop

Hi all,

Like many of you, I had no issues with monitors for years until around 2010/2011 when LED screens started to be introduced to the masses.

I'm 31 and have hopped around many OS's over the years, was predominantly Windows from 95 up to 7, then decided to give OS X a try. Within a few days, I noticed my lovely new iMac was giving me headaches and eye strain. I now discover that PWM/Temporal Dithering may be the culprit.

I am now using Windows 10 on a Dell U2414H Monitor, I can use it for hours at a time with no irritation at all. As I am quite short-sighted the DPI has been bumped up to 125% and mouse pointer has been set to large. All text is easy to read and the whole UI is larger than default which is great for me.

I would love to switch over to Linux - however I would like to know...

Do any DE's offer the same function as DPI scaling in Windows?

Is there a simple way to disable Temporal Dithering? (I am a Linux novice but after looking around online it seems editing a line in the xorg conf file should do it).

I also use standard Intel GMA integrated graphics - I know that Ubuntu has an official Intel driver available - when I installed this it did make a little difference, but there was still a slight flicker that does not happen in Windows 10, with the same Monitor and PC being used.

KM

diop
Temporal dithering:

Nvidia:
nouveau driver: https://nouveau.freedesktop.org/wiki/Dithering/
Official driver: http://us.download.nvidia.com/XFree86/Linux-x86_64/367.27/README/xconfigoptions.html
-> Option FlatPanelProperties
AMD/ATI: http://forums.guru3d.com/showthread.php?t=387362

The last time I tried Arch Linux, some weeks ago, with an older Intel GMA 3100 (DVI) both the shell and the desktop (Xfce) looked very promising in terms of eye strain. I don't have access to that machine at the moment, so this is not a 100% recommendation.

Slacor

diop on a Dell U2414H Monitor

Been using the same monitor on Linux Mint 17 for some time with Intel HD 4400 Graphics. 4400 is supposed to be a bad dithering one although I believe there is a thread around here with intel minimizing the dither.. The PWM has resolved 99% of my issues but I'm planning to use a nvidia card soon which is supposed to have dithering disabled by default.

diop Do any DE's offer the same function as DPI scaling in Windows?

Linux mint reports to have high dpi
http://segfault.linuxmint.com/2014/03/hi-dpi-support-for-cinnamon/

JTL

Slacor Ubuntu 14.04 and up (I assume) have high DPI.

Tested on Macbook Pro 2015 (2880x1800)

degen

I installed Linux Mint 18, and the Cinnamon DE has an option called "Double Pixel (HiDPI)" (or something simmilar) hidden somewhere which makes the desktop look very good on my 2460 x 1440 HP monitor. The text is very crisp and readable. I am using the subpixel antialiasing, which looks a touch better to my eyes than grayscale.

daniel_mate

degen Interesting, I'm the opposite of you, I cannot tolerate subpixel anti-aliasing and HiDPI. These two seem to be 99% of my problem. I'm trying to get "displays and rendering" back to pre 2012 era

diop

So rather than get lost in Arch I'm currently checking out the latest Manjaro Xfce with (I believe) official Intel drivers installed. Is there a way to edit xorg conf to disable temporal dithering? I have seen a similar thread somewhere on Ubuntu Forums that mentions using the xrandr command but I don't know if this is AMD/Nvidia specific or not.

The only other solution I guess is to shoot for a cheap Nvidia card and use nvidia-settings.

Another thing I've noticed is that the whites generally are much more white in Linux compared to Windows, as if there is a wider colour range, not that i'm complaining but it all just looks a little 'stark' to me compared to whites on Windows which appear less harsh and blend in with text a lot nicer. I will probably get Redshift or Flux installed soon which may help a little.

KM

diop Another thing I've noticed is that the whites generally are much more white in Linux compared to Windows, as if there is a wider colour range

Sounds like previously you looked at limited RGB color range. Then blacks are lighter and white is darker. The Linux drivers use full RGB range.

ravipra

Been fighting this battle since 2008. Few things that helped me on Linux:

Good distributions: Manjaro, MX LINUX, PCOS Linux
Desktop: KDE
Video drivers: Use non-free video drivers. Although the free versions are good, in general I feel the output is better with non-free drivers, especially on AMD graphics cards.
Kernel: Custom kernel compiled with:
- NUMA support disabled (NUMA is lot more memory intensive)
- Use SLAB instead of the default SLUB for kernel memory allocator
- Disable the encryption option in ext4
- Disable quota support for filesystems
- Disable linux guest support
- Disable memory hotplugging
- No pwm support (I think intel drm module still uses pwm)
Enable laptop_mode (either using tlp or by setting vm.laptop_mode sysctl setting)
Panel Type: In general, IPS seems better than VA and TN.
No sub-pixel AA.

I learnt a lot of very good things from PCOS Linux. They do an excellent job! It looks great out of the box!

In general, for me, it seems having a discrete graphics card (even if its in hybrid mode), a good graphics driver, a performant (less memory intensive) kernel are more important than the negative impact of dithering and pwm (I use 100% brightness level on laptops).

SLUB which is the default since 2008 seems to have impacted me negatively, although I do not have any objective data to prove.

Hope this helps.

JTL

ravipra SLUB which is the default since 2008 seems to have impacted me negatively, although I do not have any objective data to prove.

I don't see how that would make a difference unless your laptop was very slow and "bogged down" to begin with. Not saying it's impossible but it sounds like one of those far out things.

ravipra

The graphics libraries do kernel memory allocation and deallocations. So its not very surprising that if the kernel is slow or jittery you get into graphics related jitter. I want to measure this graphics jitter so that we can do objective discussions. Not successful as of today. Will keep trying.