[GUIDE] Linux Strobe Utility and Vertical Total 1350

[forivall]

Hey Blur Buster people

Through plenty of research, I have figured out how to run the equivalent of the strobe utility on Linux, and also how to set up the vertical total 1350 trick on linux.

Since I use a Nvidia card, these instructions primarily apply to Nvidia cards. Some additional tweaks may be needed for Intel, ATI and other video cards.

I have the BenQ 2411Z, so a small amount of work will be needed to support the other monitors, but that will be fairly simple. See the sections marked with , and feel free to ask for help in this thread.

Strobe Utility
The equivalent program to use is "ddccontrol" (http://ddccontrol.sourceforge.net). However, some extra configuration files are needed, and you will also need to set up some permissions.

Install ddccontrol.

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sudo apt-get install ddccontrol
# or
sudo yum install ddccontrol
# or
sudo pacman -S ddccontrol

Update the configuration files - using my fork at https://github.com/forivall/ddccontrol-db , copy the updated options file and the monitor definition file to /usr/share/ddccontrol-db

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curl -L https://github.com/forivall/ddccontrol-db/raw/master/db/options.xml | sudo tee /usr/share/ddccontrol-db/options.html
curl -L https://github.com/forivall/ddccontrol-db/raw/master/db/monitor/BNQ7F31.xml | sudo tee /usr/share/ddccontrol-db/monitor/BNQ7F31.xml

If you're not using the 2411Z, you will need to copy and modify the monitor definition file to another file in "/usr/share/ddccontrol-db/monitor/", using the monitor's Plug and Play ID. Post the output of "ddccontrol -p" in this thread if you're having troubles.

Launch ddccontrol. If it doesn't work, you need to modprobe i2c-dev and set permissions for it

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sudo modprobe i2c-dev
sudo chmod +rw /dev/i2c-*

If that works, to make the above settings permanent / persist on reboot:
(This was written for Arch Linux. It probably will work on Fedora and other newer distros, but I'm not sure for Ubuntu)

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echo 'i2c-dev' | sudo tee -a /etc/modules-load.d/modules.conf
echo 'KERNEL=="i2c-*",  MODE="0666", GROUP="i2c"' | sudo tee /etc/udev/rules.d/99-i2c-permissions.rules

(Nvidia) If it still doesn't work, add

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    Option         "RegistryDwords" "RMUseSwI2c=0x01; RMI2cSpeed=100"

to the "Section "Screen"" part of xorg.conf

Edit: There's also a command line strobe utility here: http://forums.blurbusters.com/viewtopic.php?f=13&t=557 , I just wish I found it sooner .

Vertical total 1350
If your distribution has a "/etc/X11/xorg.conf", merge the following into it. Otherwise, save the following as "/etc/X11/xorg.conf.d/30-nvidia.conf"
If you're not using the 2411Z, you will need to modify this file. Read the code!

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Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "BNQ"
    ModelName      "BenQ XL2411Z"
    ModeLine       "1920x1080_120_vt1350" 336.96 1920 1968 2000 2080 1080 1083 1088 1350 +hsync -vsync
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    # use the appropriate name for your card
    BoardName      "GeForce GTX 760"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "Stereo" "0"
    # Option         "metamodes" "DPY-EDID-db993222-ec3f-cd40-b91a-533c4d64c5f7: 1920x1080_120_vt1350 +0+0"
    # you can adjust the above option accordingly for multiple monitors, for example, I use:
    # Option         "metamodes" "DVI-I-1: 1920x1080_120_vt1350 +0+0, DVI-D-0: nvidia-auto-select +1920+0"
    Option         "SLI" "Off"
    Option         "MultiGPU" "Off"
    Option         "RegistryDwords" "RMUseSwI2c=0x01; RMI2cSpeed=100"
    # TODO: EDID UUID will be different for other models. This will only apply to the XL2411Z connected via DVI
    # for HDMI, use DPY-EDID-8cd9192b-aee5-dfcf-b796-81558db3eee3
    # VGA is also different.
    # use `nvidia-settings -q dpys` to find the EDID UUID name to use for your model
    Option         "ModeValidation" "DPY-EDID-db993222-ec3f-cd40-b91a-533c4d64c5f7: AllowNonEdidModes,NoMaxPClkCheck,NoEdidMaxPClkCheck,NoHorizSyncCheck;"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Restart your computer or your X server. If it doesn't seem like it's running in 1350 mode after you restart, use the following:
Be prepared to restart your computer if this fails!

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nvidia-settings --assign CurrentMetaMode="DPY-EDID-db993222-ec3f-cd40-b91a-533c4d64c5f7: 1920x1080_120 +0+0"

Enjoy!

[forivall]

If you have problems, make sure to include:

Monitor model
Output of "LANG= LC_ALL= ddccontrol -p -c -d"

Linux distro and version (e.g. Linux Mint 15.1)
Output of "lsb_release -a"
Output of "uname -a"

Graphics card (e.g. Nvidia 760)
Output of "lspci|grep VGA"

Graphics driver (e.g. nouveau, nvidia)
Output of "lsmod"
(if nvidia)
Output of "nvidia-settings -q dpys"
Output of "nvidia-xconfig --query-gpu-info"

[rayno206]

I'm sorry to say this, I'm new to Ubuntu, I'm using ubuntu, and as I follow your thread, I can't find a way to install the ddccontrol, can you help me out with installing the Strobe Utility and Vertical 1350 trick, I have the XL2411Z BenQ and using nvidia GTX 970

[forivall]

@rayno206

Hmm, it looks like recent versions of ubuntu no longer have ddccontrol in the default repository. See if you can install the deb files from https://launchpad.net/ubuntu/+source/ddccontrol. If that doesn't work, you can also try the blstrobe tool described here http://forums.blurbusters.com/viewtopic.php?f=13&t=557 and downloadable here: https://github.com/fhunleth/blstrobe . However, you'll need to build that from source; if you haven't built software before, you'll need to install build-essential before running the instructions on github.

The vertical total 1350 trick should still work without ddccontrol.

[lexlazootin]

I want to like linux so much but I swear they try to make it less usable for the everyday man. :sadpanda:

[rayno206]

@forivall, I tried all of your suggestions, I even tried to install the github blstrobe, but when ever I tried to run the command sudo blstrobe -e -t 1500 to set the parameters for my monitor, it says "blstrobe: No displays detected. Make sure that you have run "sudo modprobe i2c-dev" and are calling this as root." even though I did run the sudo modprobe i2c-dev comman

[forivall]

Could you please include the information mentioned in the second post? Thanks.

[asunawa]

Got it working on Debian Jessie. Cool tool, i like the gui version of ddccontrol.
Very easy to adjust the strobe lenght and strobe phase.
I would like to try this with VT1500 and 125hz, but not sure how to create a modeline for that.

[Falkentyne]

For 125hz,
Use VT 1500 if on a 24"
Use VT 1498 if on 27" XL2720Z
Make sure you drop the timings from HT 2200 to 2080 to avoid swimming pixels.
and front porch should be 48,3 (default is 88,4), sync width should be 32,5 (instead of 44,5)

I got strobe sync errors at 125hz (almost every time) on XL2720Z at VT 1499, 1500, 1501 and 1502, but 1498 is flawless. When changing a a gamer profile with the S-switch at VT 1498, I see it temporarily lose sync for a second or two then it kicks back in and works every time. At 1500/1502, the screen pulsates and acts like the strobe pulse is incorrect. The same thing happens when trying to use lightboost mode with an incorrect VT e.g. 125 hz at VT 1155 will do the same thing (correct VT is 1149 for 120hz, and up to VT 1180 should work at 120hz).

I get rare (much rarer than 125hz) sync errors at VT 1502 at 120hz but VT 1500 is always fine.
Similarly, VT 1501 is fine at 85hz, but VT 1502 and VT 1500 cause strange issues and pulsating (at 100hz, 1500 and 1502 are perfect).

[asunawa]

Would this be correct?

Horizontal timings | Vertical timings:

Resolution: 1920 | Resolution: 1080
Front porch: 48 pixels | Front porch: 3 lines
Sync pulse: 32 pixels | Sync pulse: 5 lines
Back porch: 80 pixels | Back porch: 412 lines