Cannot run Samsung T240HD at 1920x1200

[jellyfisharepretty]

Hi everyone

I have been searching the web intensely for a solution to this problem, but alas nothing seems to work. I got this new monitor, a Samsung T240HD, which has a native resolution of 1920x1200. According to the Samsung user manual for this monitor, the maximum resolution is 1920x1200@60Hz with horizontal freq. range 30-81 kHz and vertical freq. range 56-75 Hz with maximum pixel clock 162.00 MHz.

At first I couldn't get beyond 1680x1050 with a DVI cable. I then read on Samsung's tech support website, and other posts, that single-link DVI cable won't allow me past this resolution because of bandwidth limitations, so I hooked up an analog cable, which got me to a maximum resolution of 1920x1080. A dual-link DVI cable won't work, since this Monitor only supports a single-link connection.

This, however, is not the monitor's native resolution and gives me an image quite stretched vertically, which I find unacceptable.

I have tried many xorg.conf tweaks to get a 1920x1200 resolution choice to appear in the nvidia-settings utility, but to no avail. The highest that still appears is 1920x1080. I am using an Nvidia Geforce 8800GTS card with the Nvidia 180.44 linux drivers on a fresh, clean Jaunty install. I was hoping switching to Jaunty would solve the problem, but I had the same problem in Feisty.

Here's what my xorg.conf file currently looks like :

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
EndSection

Section "Module"
    Load           "glx"
EndSection

Section "ServerFlags"
    Option         "Xinerama" "0"
    Option         "DontZap"  "false"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Monitor0"
    VendorName     "Samsung"
    ModelName      "T240HD"
    HorizSync       30.0 - 81.0
    VertRefresh     56.0 - 75.0
    ModeLine       "1920x1200_60.00" 193.16 1920 2048 2256 2592 1200 1201 1204 1242 -Hsync +Vsync
    Modeline       "1920x1200_59.95"  192.99  1920 2048 2256 2592  1200 1201 1204 1242  -HSync +Vsync
    Modeline       "1920x1200_50.00"  158.08  1920 2032 2240 2560  1200 1201 1204 1235  -HSync +Vsync
    Modeline       "1680x1050_60.00"  147.14  1680 1784 1968 2256  1050 1051 1054 1087  -HSync +Vsync
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8800 GTS"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "TwinView"     "0"
    Option         "MetaModes"    "CRT: 1920x1200_60.00 +0+0; CRT: 1920x1200_59.95 +0+0; CRT: 1920x1200_50.00 +0+0; CRT: 1680x1050_60.00 +0+0"
    Option         "UseEdidFreqs" "false"
    Option         "NoLogo"       "true"
    Option         "Coolbits"     "1"
    Option         "TripleBuffer" "true"
    SubSection     "Display"
        Depth       24
	Modes       "1920x1200_60.00" "1920x1200_59.95" "1920x1200_50.00" "1680x1050_60.00"
    EndSubSection
EndSection

, where I have generated modelines using the gtf command-line utility for 1920x1200@60Hz, 1920x1200@59.95Hz, 1920x1200@50Hz and 1680x1050@60Hz.

I was trying to implement the solution posted in this thread for another Samsung monitor with quite similar specs, but that didn't work.

I told the nvidia driver to stop using EDID for frequencies, and use the ones specified in the monitor section instead (which I took right out of the monitor's user manual), but that had no effect either.

Did I miss anything ? I'm running out of ideas here Hope someone can help...

[jellyfisharepretty]

bump

[coffeecat]

I experienced a completely unrelated issue with the nvidia 180 driver here which was solved by downgrading to the 173 driver. According to the notes in Synaptic for the nvidia-glx-173 driver your Geforce 8800GTS card is supported, but you might want to check this. Have you tried the 173 driver? Since I managed to unearth one (very) obscure bug with the 180 driver, you may have come across another.

Have you got (or got access to) a Windows machine with the 180 nvidia driver? Since much of code would be shared between the Linux and Windows drivers, it might be interesting to see if this problem with your monitor is duplicated in Windows. But if it were you'd think Samsung would know about it by now.

At first I couldn't get beyond 1680x1050 with a DVI cable. I then read on Samsung's tech support website, and other posts, that single-link DVI cable won't allow me past this resolution because of bandwidth limitations, so I hooked up an analog cable,

It could be argued that it's not fit for purpose if it doesn't run at optimum resolution with DVI. Would consumer laws where you are permit you to return this? My 24" BenQ monitor works at 1920x1200 no problem with Ubuntu, Windows and Mac Mini, analogue or DVI, and through a KVM switch.

[jellyfisharepretty]

Thanks for your input, coffeecat. I think the idea of trying the 173 driver is certainly worth a try. Will report on my findings once I do that.

As for windows, I'll have to install XP on my second hard drive, and apply all the drivers and stuff... that will take time. But I think I'll also try it if downgrading the Nvidia driver doesn't work.

I was certainly disappointed to learn Samsung did not include a dual-link DVI capability with this monitor, which effectively limits the resolution to 1920x1080 on DVI, according to what I have read. Still, even this choice of resolution did not appear when I have a DVI cable connected.

I don't know if consumer laws would allow me to return this. I suspect they would, since this monitor was advertised supporting a digital connection with a resolution of 1920x1200 (and clearly doesn't). Personally, using the analog cable, as long as I can run at the monitor's native resolution, is an acceptable work-around for me.

[coffeecat]

Usual caveat - IANAL - but I understand that consumer law here in the UK means that if you buy from a distance seller (usually over the internet, delivered to your door) you have an absolute right to return the item within 30 days for a complete refund, no reason given. You are, I believe, liable for return carriage though.

Some suppliers try to wriggle out of this, of course. The better ones just accept this is part of their trading environment and don't quibble.

I don't know whether this is true in Canada, or just a UK quirk, but that might be worth checking out if you've had the monitor for only a short time.

[jellyfisharepretty]

Switching to the 173 drivers had no effect. I still can get to 1920x1080 at most. Will try with Windows next.

[jellyfisharepretty]

Update... I tried with windows by connecting my laptop (geforce 9500m) with an analog vga cable. Still can't get to the native resolution, so this is beginning to look like some kind of hardware problem with my monitor I guess...

[ghmerrill]

It's not a hardware problem with your monitor. I just got a Lenovo Y 550 and put Ubuntu on it. I have exactly the same problem with the T240. I've posted in another thread asking for help as well, but no one seems to have a solution.

On my Dell laptop Windows system, Windows simply detects the monitor, the optimal resolution, and everything is fine. On Linux, it just isn't happening. It's a Linux problem of some sort.

I'm really impressed with Ubuntu Linux and am going back to using *NIX after a number of years. But it still seems that one of the significant holes in Linux is hardware support. It's a lot better now, but still problematic.

[ghmerrill]

This is particularly puzzling if you look at the thread "Samsung T240" how to enable 60 Hz where it appears that the correct resolution is achieved under Linux without a problem. I wonder if it's a version problem.

Very frustrating. I haven't experimented much with this yet, but no one seems to have any genuine insight into it. We're seeing exactly the same problem on different laptops with different video cards -- and it works fine on Windows and apparently on at least one Linux install.

[jellyfisharepretty]

Resurrecting this thread from the dead...

I have found out what exactly might be wrong ! This thread led me to it.

The EDID my monitor provides seems to be the EDID of a 22in Samsung monitor of maximum resolution 1680x1050 (might be the EDID of the Samsung T220HD). Here's what I got when I read the EDID off the monitor (Using the Monitor Asset Manager utility on Windows):

Monitor
Model name............... SyncMaster
Manufacturer............. Samsung
Plug and Play ID......... SAM03F0
Serial number............ HVLQC00122
Manufacture date......... 2008, ISO week 50
-------------------------
EDID revision............ 1.3
Input signal type........ Digital
Color bit depth.......... Undefined
Display type............. RGB color
Screen size.............. 470 x 300 mm (22.0 in)
Power management......... Active off/sleep
Extension blocs.......... None
-------------------------
DDC/CI................... Supported
MCCS revison............. 2.0
Display technology....... TFT
Controller............... Mstar 0x1400
Firmware revision........ 0.1
Firmware flags........... 0x00000001
Active power on time..... Not supported
Power consumption........ Not supported
Current frequency........ 65.54kHz, 0.00Hz

Color characteristics
Default color space...... Non-sRGB
Display gamma............ 2.20
Red chromaticity......... Rx 0.640 - Ry 0.330
Green chromaticity....... Gx 0.300 - Gy 0.600
Blue chromaticity........ Bx 0.150 - By 0.060
White point (default).... Wx 0.313 - Wy 0.329
Additional descriptors... None

Timing characteristics
Horizontal scan range.... 30-81kHz
Vertical scan range...... 56-75Hz
Video bandwidth.......... 150MHz
CVT standard............. Not supported
GTF standard............. Not supported
Additional descriptors... None
Preferred timing......... Yes
Native/preferred timing.. 1680x1050p at 60Hz (16:10)
Modeline............... "1680x1050" 146.250 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync

Standard timings supported
720 x 400p at 70Hz - IBM VGA
640 x 480p at 60Hz - IBM VGA
640 x 480p at 67Hz - Apple Mac II
640 x 480p at 72Hz - VESA
640 x 480p at 75Hz - VESA
800 x 600p at 56Hz - VESA
800 x 600p at 60Hz - VESA
800 x 600p at 72Hz - VESA
800 x 600p at 75Hz - VESA
832 x 624p at 75Hz - Apple Mac II
1024 x 768p at 60Hz - VESA
1024 x 768p at 70Hz - VESA
1024 x 768p at 75Hz - VESA
1280 x 1024p at 75Hz - VESA
1152 x 870p at 75Hz - Apple Mac II
1680 x 1050p at 60Hz - VESA STD
1280 x 1024p at 60Hz - VESA STD
1280 x 960p at 60Hz - VESA STD
1152 x 864p at 75Hz - VESA STD

Now I can think of two solutions.

1) I try to contact Samsung so they can either replace the monitor or update its firmware so that it has the correct EDID. It is a shame that Samsung does not make its firmware available as I could just as easily update it myself using the USB port at the back of the monitor and using the software update option in the monitor menu.

2) I somehow fool Ubuntu and the Nvidia drivers into not using EDID from the monitor, providing the information myself (in the form of lines in xorg.conf, or some other way ?). As can be seen from my first post, I already tried doing this without much success.

Does anyone know of a way to specify the use of a different EDID (other than lines in xorg.conf - which didn't seem to work) ?

If anyone has a Samsung T240HD, can you post and attach your EDID file in binary format ? This can be extracted using the read-edid package, probably by executing

# sudo get-edid > edid.bin
[Edit] I don't think this is the right way of using get-edid. In fact I don't think that command will work. But am not sure how to use it.

or by using the Monitor Asset Manager utility on Windows.

Thanks!