LinuxQuestions.org - 100Hz refresh on 1024x768 resolution

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100Hz refresh on 1024x768 resolution

Amazing, after 2 days working with Knoppix we solved ALL our problems that prevented us from regular work on computer.

Just one question remained, and I *really* want to solve it.

Why the KDE control center does not allow me using 100Hz together with 1024x768 screen resolution (my nVidia GeForce something video card allows it)?

I can set 800x600 with 100Hz and 1024x768 with 85Hz maximum (!).

Please help me to solve this problem.

Normally, you can set any mode that is supported by both your graphics card and monitor.

So, at a guess, your monitor claims not to support that resolution at that frequency. Using your monitor out of specification can cause it to wear out very quickly.

Check the monitor settings in YaST; it's quite common for monitors to lie about their frequency ranges.

Please post your monitor model and graphics card/chipset models if you think there is a worse problem. You can get these from YaST in the hardware info bit.

Edit: Sorry; you're using Knoppix. YaST is SuSE's setup tool, and doesn't apply here. Sorry if I confused you, but Knoppix probably will have some equivalent hardware setup utility.

Is there a specific reason why you want to run the monitor at >100hz. Generally, on CRTs, 75-85 hz is good enough and running the monitor at too high of a refresh rate can degrade the image quality.

What is YaST? I believe the monitor support 100Hz at 1024x768 and even more - it is LG Flatron 786PFs.

The video card is nVidia GeForce something (I have to see it during a reboot), 64M at least.

Generally, I truly like working with 100Hhz vertical refresh rate, I think I feel it - I realize this violates some school laws of physics as refresh rate of human eye is 70-80Hz only.

Working 2 days on monitor with 85Hz refresh rate is bad for my eyes, indeed.

Quote:

Originally posted by leg_of_pinguin
What is YaST? I believe the monitor support 100Hz at 1024x768 and even more - it is LG Flatron 786PFs.

The video card is nVidia GeForce something (I have to see it during a reboot), 64M at least.

Generally, I truly like working with 100Hhz vertical refresh rate, I think I feel it - I realize this violates some school laws of physics as refresh rate of human eye is 70-80Hz only.

Working 2 days on monitor with 85Hz refresh rate is bad for my eyes, indeed.

I checked the specs of your monitor :

Recommended resolution is 1024x768 @ 85 hz
Max resolution is 1280x1024 @ 66 hz

It doesn't appear that the monitor officially supports 1024x768 at >= 100hz which means that running it that high could cause damage to the monitor.

I couldn't find detailed specs however, just a general overview of the refresh rate and such. Most of the sites that Google returned were in Hebrew. It also appears that the monitor was sold under the Mag name but the Mag one with the same model number has a higher max resolution :confused:

Thanks for research, it is MAG indeed !

Is there any possibility to operate such a monitor at 100Hz? Even though it is not recommended?

Quote:

Originally posted by leg_of_pinguin
Thanks for research, it is MAG indeed !

Is there any possibility to operate such a monitor at 100Hz? Even though it is not recommended?

If it's the Mag one you should be fine. Are you using Knoppix still?

Also can you post the contents of the /etc/X11/xorg.conf or /etc/X11/XFree-4.conf files? (you'll have one or the other)

Thanks for answer. And sorry for the delay - I was not near my computer at this week.
I would like to finish with this 100Hz question, if possible.

Code:

root@temple:/etc/X11# ls

X                              newxserver.xserver-ggi

XF86Config                    newxserver.xserver-i128

XF86Config-4                  newxserver.xserver-mach32

XF86Config-4.bak              newxserver.xserver-mach64

XF86Config-4.in                newxserver.xserver-mach8

XF86Config-4~                  newxserver.xserver-mono

XF86Config.in                  newxserver.xserver-p9000

XftConfig                      newxserver.xserver-s3

Xloadimage                    newxserver.xserver-s3v

Xresources                    newxserver.xserver-svga

Xserver.xserver-common-backup  newxserver.xserver-vga16

Xsession                      newxserver.xserver-w32

Xsession.d                    rgb.txt

Xsession.options              rstart

Xwrapper.config                ru

app-defaults                  rxvt.menu

cursors                        sawmill

default-display-manager        serverconfig

fluxbox                        starthere

fonts                          sysconfig

fs                            twm

icewm                          xawtvrc

ja_JP.eucJP                    xdm

ko_KR.eucKR                    xfce4

newxserver.xserver-3dlabs      xinit

newxserver.xserver-8514        xkb

newxserver.xserver-agx        xserver

newxserver.xserver-fbdev      xsm

What is the target file?

Thanks!

It looks like this (display-related sections):

Code:

# Auto-generated by mkxf86config



Section "Monitor"

        Identifier  "Monitor0"

        VendorName        "GSM"

        ModelName        "GSM4313"

        HorizSync 30 - 71 # DDC-probed

        VertRefresh 50 - 160 # DDC-probed

        # These are the DDC-probed settings reported by your monitor.

        # 1280x1024, 75.0Hz; hfreq=79.98, vfreq=75.03

        ModeLine "1280x1024"        135.00 1280 1296 1440 1688 1024 1025 1028 1066 +hsync +vsync

        # 1024x768, 85.0Hz; hfreq=68.68, vfreq=85.00

        ModeLine "1024x768"        94.50 1024 1072 1168 1376  768  769  772  808 +hsync +vsync

        # 1024x768, 75.0Hz; hfreq=60.02, vfreq=75.03

        ModeLine "1024x768"        78.75 1024 1040 1136 1312  768  769  772  800 +hsync +vsync

        # 1024x768, 75.0Hz; hfreq=60.02, vfreq=75.03

        ModeLine "1024x768"        78.75 1024 1040 1136 1312  768  769  772  800 +hsync +vsync

        # 1024x768, 70.0Hz; hfreq=56.48, vfreq=70.07

        ModeLine "1024x768"        75.00 1024 1048 1184 1328  768  771  777  806 -hsync -vsync

        # 1024x768, 60.0Hz; hfreq=48.36, vfreq=60.00

        ModeLine "1024x768"        65.00 1024 1048 1184 1344  768  771  777  806 -hsync -vsync

        # 800x600, 85.0Hz; hfreq=53.67, vfreq=85.06

        ModeLine "800x600"        56.25  800  832  896 1048  600  601  604  631 +hsync +vsync

        # 800x600, 75.0Hz; hfreq=46.88, vfreq=75.00

        ModeLine "800x600"        49.50  800  816  896 1056  600  601  604  625 +hsync +vsync

        # 800x600, 75.0Hz; hfreq=46.88, vfreq=75.00

        ModeLine "800x600"        49.50  800  816  896 1056  600  601  604  625 +hsync +vsync

        # 800x600, 60.0Hz; hfreq=37.88, vfreq=60.32

        ModeLine "800x600"        40.00  800  840  968 1056  600  601  605  628 +hsync +vsync

        # 800x600, 56.0Hz; hfreq=35.16, vfreq=56.25

        ModeLine "800x600"        36.00  800  824  896 1024  600  601  603  625 +hsync +vsync

        # 640x480, 85.0Hz; hfreq=43.27, vfreq=85.01

        ModeLine "640x480"        36.00  640  696  752  832  480  481  484  509 -hsync -vsync

        # 640x480, 75.0Hz; hfreq=37.50, vfreq=75.00

        ModeLine "640x480"        31.50  640  656  720  840  480  481  484  500 -hsync -vsync

        # 640x480, 75.0Hz; hfreq=37.50, vfreq=75.00

        ModeLine "640x480"        31.50  640  656  720  840  480  481  484  500 -hsync -vsync

        # 640x480, 72.0Hz; hfreq=37.86, vfreq=72.81

        ModeLine "640x480"        31.50  640  656  696  816  480  481  484  504 -hsync -vsync

        # 640x480, 60.0Hz; hfreq=31.47, vfreq=59.94

        ModeLine "640x480"        25.17  640  648  744  784  480  482  484  509 -hsync -vsync

        # Extended modelines with GTF timings

        # 640x480 @ 100.00 Hz (GTF) hsync: 50.90 kHz; pclk: 43.16 MHz

        ModeLine "640x480"  43.16  640 680 744 848  480 481 484 509  -HSync +Vsync

        # 768x576 @ 60.00 Hz (GTF) hsync: 35.82 kHz; pclk: 34.96 MHz

        ModeLine "768x576"  34.96  768 792 872 976  576 577 580 597  -HSync +Vsync

        # 768x576 @ 72.00 Hz (GTF) hsync: 43.27 kHz; pclk: 42.93 MHz

        ModeLine "768x576"  42.93  768 800 880 992  576 577 580 601  -HSync +Vsync

        # 768x576 @ 75.00 Hz (GTF) hsync: 45.15 kHz; pclk: 45.51 MHz

        ModeLine "768x576"  45.51  768 808 888 1008  576 577 580 602  -HSync +Vsync

        # 768x576 @ 85.00 Hz (GTF) hsync: 51.42 kHz; pclk: 51.84 MHz

        ModeLine "768x576"  51.84  768 808 888 1008  576 577 580 605  -HSync +Vsync

        # 768x576 @ 100.00 Hz (GTF) hsync: 61.10 kHz; pclk: 62.57 MHz

        ModeLine "768x576"  62.57  768 816 896 1024  576 577 580 611  -HSync +Vsync

        # 800x600 @ 100.00 Hz (GTF) hsync: 63.60 kHz; pclk: 68.18 MHz

        ModeLine "800x600"  68.18  800 848 936 1072  600 601 604 636  -HSync +Vsync

        # 1024x768 @ 100.00 Hz (GTF) hsync: 81.40 kHz; pclk: 113.31 MHz

        ModeLine "1024x768"  113.31  1024 1096 1208 1392  768 769 772 814  -HSync +Vsync

        # 1152x864 @ 60.00 Hz (GTF) hsync: 53.70 kHz; pclk: 81.62 MHz

        ModeLine "1152x864"  81.62  1152 1216 1336 1520  864 865 868 895  -HSync +Vsync

        # 1152x864 @ 85.00 Hz (GTF) hsync: 77.10 kHz; pclk: 119.65 MHz

        ModeLine "1152x864"  119.65  1152 1224 1352 1552  864 865 868 907  -HSync +Vsync

        # 1152x864 @ 100.00 Hz (GTF) hsync: 91.50 kHz; pclk: 143.47 MHz

        ModeLine "1152x864"  143.47  1152 1232 1360 1568  864 865 868 915  -HSync +Vsync

        # 1280x960 @ 72.00 Hz (GTF) hsync: 72.07 kHz; pclk: 124.54 MHz

        ModeLine "1280x960"  124.54  1280 1368 1504 1728  960 961 964 1001  -HSync +Vsync

        # 1280x960 @ 75.00 Hz (GTF) hsync: 75.15 kHz; pclk: 129.86 MHz

        ModeLine "1280x960"  129.86  1280 1368 1504 1728  960 961 964 1002  -HSync +Vsync

        # 1280x960 @ 100.00 Hz (GTF) hsync: 101.70 kHz; pclk: 178.99 MHz

        ModeLine "1280x960"  178.99  1280 1376 1520 1760  960 961 964 1017  -HSync +Vsync

        # 1280x1024 @ 100.00 Hz (GTF) hsync: 108.50 kHz; pclk: 190.96 MHz

        ModeLine "1280x1024"  190.96  1280 1376 1520 1760  1024 1025 1028 1085  -HSync +Vsync

        # 1400x1050 @ 60.00 Hz (GTF) hsync: 65.22 kHz; pclk: 122.61 MHz

        ModeLine "1400x1050"  122.61  1400 1488 1640 1880  1050 1051 1054 1087  -HSync +Vsync

        # 1400x1050 @ 72.00 Hz (GTF) hsync: 78.77 kHz; pclk: 149.34 MHz

        ModeLine "1400x1050"  149.34  1400 1496 1648 1896  1050 1051 1054 1094  -HSync +Vsync

        # 1400x1050 @ 75.00 Hz (GTF) hsync: 82.20 kHz; pclk: 155.85 MHz

        ModeLine "1400x1050"  155.85  1400 1496 1648 1896  1050 1051 1054 1096  -HSync +Vsync

        # 1400x1050 @ 85.00 Hz (GTF) hsync: 93.76 kHz; pclk: 179.26 MHz

        ModeLine "1400x1050"  179.26  1400 1504 1656 1912  1050 1051 1054 1103  -HSync +Vsync

        # 1400x1050 @ 100.00 Hz (GTF) hsync: 111.20 kHz; pclk: 214.39 MHz

        ModeLine "1400x1050"  214.39  1400 1512 1664 1928  1050 1051 1054 1112  -HSync +Vsync

        # 1600x1200 @ 100.00 Hz (GTF) hsync: 127.10 kHz; pclk: 280.64 MHz

        ModeLine "1600x1200"  280.64  1600 1728 1904 2208  1200 1201 1204 1271  -HSync +Vsync

        # 1920x1200 @ 60.00 Hz (GTF)  hsync: 74.52; pclk: 193.16 MHz

        Modeline "1920x1200" 193.16  1920 2048 2256 2592  1200 1201 1204 1242  -HSync +HSync

EndSection

Code:

# Standard Server

Section "Screen"

    Driver      "svga"

    Device      "My Video Card"

    Monitor    "Monitor0"

    Subsection  "Display"

        Modes "1024x768" "800x600" "640x480"

        ViewPort 0 0

    EndSubsection

EndSection



# Accel. Server(s)

Section "Screen"

    Driver      "accel"

    Device      "My Video Card"

    Monitor    "Monitor0"

    Subsection  "Display"

        Modes "1024x768" "800x600" "640x480"

        ViewPort 0 0

    EndSubsection

EndSection



# Fallback

Section "Screen"

    Driver      "vga16"

    Device      "My Video Card"

    Monitor    "Monitor0"

    Subsection  "Display"

        Modes "1024x768" "800x600" "640x480"

    EndSubsection

EndSection

What do I change?

The config looks OK, what you need is to generate a Modeline. Use xvidtune program, play with it (you may need a while to get used to it, but it's easy). When you have settings that are good, use 'Show' button and copy the modline you get to XF86Config - start line with 'Modeline' and then copy exactly what you got.

http://koala.ilog.fr/cgi-bin/nph-colas-modelines is a modeline generator that you might find easier.

From the parameters in the file, the best your monitor will support is 87Hz at 1024x768:

ModeLine "1024x768" 98.97 1024 1072 1312 1408 768 770 782 808 #87Hz

If you are prepared to overclock your monitor, you could try this for 100Hz, but note that your monitor will die prematurely (guarenteed) and you will certainly invalidate the warranty:

ModeLine "1024x768" 113.76 1024 1072 1312 1408 768 770 782 808 #100Hz

NB: This assumes that the rates given in the config file are, in fact, the right ones for your monitor. This is not necessarily always the case.

The problem is solved.

When I saw that I can change the settings, I decided finally to work with recommended ones :)

Thank you all.