Nvidia + Matrox TripleHead2Go with resolution 5040x1050!

[ikonfokkah]

Hi,

Im just wondering:

Would triplehead2go work with 3x1980x1080?

[JaXXoN]

Originally Posted by ikonfokkah

Would triplehead2go work with 3x1980x1080?

1980x1080 is a pretty un-typical resolution - I guess you mean 1920x1080, right?

3x1920x1080 should work fine.

"dilzz" success reported 3x1920x1200:
http://www.nvnews.net/vbulletin/showthread.php?t=127402
(specifically check postings #8, #15 and #31).

For further details, you may like to check
http://www.nvnews.net/vbulletin/showthread.php?t=106517
http://www.nvnews.net/vbulletin/showthread.php?t=133740 (post #2)

Basically, you connect one 1920x1080 LCD straight to the first DVI output
of the video card and the other two 1920x1080 LCDs to the seconds DVI
output through the TH2G. Means, actually a DualHead2Go would be sufficient,
but this device has a VGA input, only. So for a "pure" digital solution,
you may prefer running a TH2G in dual head mode since it has a DVI
input, too).

regards

Bernhard

[ikonfokkah]

Hi,

Sounds like a plan for windows, but how would that work for games? ie: fullscreen d3d.

[JaXXoN]

Originally Posted by ikonfokkah

Sounds like a plan for windows, but how would that work for games? ie: fullscreen d3d.

On Linux, you can apply the "TwinViewXineramaInfoOveride" option in order
to define user specific screen setups, so gaming is basically not a problem
(check positing #26 in this thread).

I didn't yet tried out the above described setup on Microsoft Windows, but
using the nvidia configuration tool on windows, it should be possible to
create a user defined video mode for the second video output of the graphics
card in order to driver the TH2G with 3840x1080 (2x1920x1080). Then,
as long as it possible to span games across two LCDs with twinview,
then it should also be possible to span it across one LCD and one TH2G
(where the other two LCDs are connected to) - for the card/driver the
TH2G just looks like a display with high resolution. Means: if games worked
with twinview, then they will also work with the twinview+TH2G setup.
However, I don't know if something like "TwinViewXineramaInfoOveride"
exists for windows, so maximizing screens on the desktop may not work
as desired.

I have no practical experiences with gaming on windows, but from what
I have read so far, for that platform, it should be better to just use two
video cards (four outputs altogether) rather than purchasing a fairly
expensive TH2G - this way, d3d games should nicely just span across
all displays (unless you are using SLI), right? Note: this two video card
variant has quite a number of limits on Linux, thus the need for a different
solution.

regards

Bernhard

[JWS]

Dear JaXXoN,

I'm having trouble with my TH2Go too, like many others it appears. I'm using XP Pro and a 8800 GTS card with 3 20"ACER V203Wabd monitors. According to the Matrox Compatibility tool my system should be able to run the highest resolution. However When using 5040x1050 the bottom part and the right part of the window disappear. ACER support claims that it is due to the fact that my screens do not support 57Hz (which in their opinion is a rather unusual frequency for digital). And they "blame" Matrox. Matrox on the other hand points to my graphics card and the drivers. So everyone is pointing to another.

I've come across this site and this thread and wonder if you could help me. Is there a possibility to get the resolution wanted or do I have to look out for other monitors (22"?) and if so, which??

I'm not exactly a pc wizzard so if it comes to altering files etc. please keep it idiot proof.

Best regards,

JWS

[JaXXoN]

Hi JWS,

As you probably read, I had a similar problem with my V223Wbd LCDs,
but for me it was only the bottom part that disappeared because the
panel only recognized the video signal as 1680x1024. The spec of the
LCD says "Frequency (Horizontal/Vertical): 30-80KHz/55-75Hz", means
that the displays should work all the range from 55 to 75 Hz. However when
asking Acer support the reply was the the native resolution (1680x1050)
is only support at 60Hz. Anyway, even if the LCD would provide the
right timing parameters via EDID/I2C, as far as I can tell, the TH2G ignores
that and just generates it's own timing, which works for some LCDs but not
for others. However, it is possible to influence the TH2G output timing by
supplying a different input timing to the TH2G: when installing the matrox
tools on the PC, it also creates a custom resolution for the 5040x1050
setup - you can now try to play around with those timing values through
the nvidia configuration tool (check for the "custom resolutions" dialog,
please check earlier posts, above for details), i.e. for me I got the 26
missing pixels on the bottom back after increasing the value for "vertical
total" from 1066 to 1073.

Here's a pretty old but still up to date document detailing what
each of the timing value does and how to potentially fix problems
like the one you have:
http://www.ibiblio.org/pub/Linux/doc...-Timings-HOWTO

Good luck!

Bernhard

[JWS]

Bernhard,

thank you. I will have another look, though I must say that the document you pointed out looks very technical at first glance. I don't know if I can understand that.

JWS

[JaXXoN]

Originally Posted by JWS

I must say that the document you pointed out looks very technical at first glance. I don't know if I can understand that.

I added the link just as a reference in case you might be curious what the timing
values stand for when playing around with them. The document is in deed big,
but technically it's actually pretty simple: Assume you have an old CRT (like
an old TV). In order to build the picture, there's an electronic beam sweeping from
left to right in order to form a line of the frame and this is repeated from top
to bottom to build all lines. Now in order to tell when to start the next line or the
next frame, you need horizontal and vertical sync signals. So for example, you
might have the following timing values:

Horizontal active pixel: 1680
Horizontal sync start: 1784
Horizontal sync end: 1960
Horizontal total: 2240

Vertical active lines: 1050
Vertical sync start: 1053
Vertical sync end: 1059
Vertical Total: 1089

Pixel Clock: 146.25 MHz

Where
sync start - active pixel = front porch (H:104, V:3)
sync end - sync start = sync width (H:176, V:6)
Horizontal Frequency = Pixel Clock / Horizontal total (65.3Khz)
Vertical Frequency = Pixel Clock / Horizontal total / Vertical Total (59.95 Hz)

So in your case, i'd first try to increase the value for "Vertical Total" in
order to hopefully fix the missing pixels on the bottom. Then you might
try to fix the pixels on the side by playing with the Horizontal front porch
and sync width. I wouldn't recommend changing the Horizontal total
because the TH2G doesn't like that (picture gets messed up).
You may also try to play with the pixel clock value (the higher, the better,
at least for the 5040x1050 mode of the TH2G).

good luck

Bernhard

[JaXXoN]

Hi!

Just for those who might be interested, I have figured out how to get
bezel management support working for the TH2G and twinview on
Linux by monitoring the USB traffic between the Matrox setup tool and
the TH2G, and by defining special metamodes:


Preliminary Bezel Management Support for Linux

Bezel Management through TH2G

The Matrox TripleHead2Go allows to "bridge the gaps"
between displays, in order to avoid distortion.
This features is called "Bezel Management".
For details, please check the following web page:
http://www.matrox.com/graphics/surro...product/bezel/

However, Matrox supports this features only for Windows
and Mac. With some effort, it was possible to figure out
the parts of the USB protocol necessary to create preliminary
support for Linux.

Limitations

• At the moment, only the 5040x1050 widescreen mode is supported.
  Using th2gctrl for other modes will mix up the output! More monitoring
  of the USB traffic is required for full support.
• th2gctrl currently need superuser right, so you need to use sudo
  or set the suid bit. I'm pretty sure this could be avoided by creating an
  appropriate udevd rule.
• The maximum number of supported TH2G boxes is currently
  hard-coded to 32. This should be sufficient for most applications :-)

Compiling th2gctrl

The source code for th2gctrl is attached to this posting
(th2gctrl.c).

On Fedora, you may need to install the package "libusb-devel"
prior to compile th2gctrl. The name of this package my differ
for other Linux distributions

gcc -Wall -O2 -o th2gctrl th2gctrl.c -lusb

Running th2gctrl

Here's an example on how to enable bezel support for two TH2Gs:

sudo ./th2gctrl -n 0 -l 72 -r 72
sudo ./th2gctrl -n 1 -l 72 -r 72

This will shift the output of the left and the right
displays by 72 pixel towards the center display.
Means: on the left and right display 72 pixel will
be hidden under the frames of the LCDs, so that
you will only see 1608 pixel instead of 1680 pixel
for an LCD with a resolutions of 1680x1050 pixel.

Please note that i got distortion when applying more
than 72 pixel. My assumption is that my Acer V223Wbd
LCDs don't like the timing generated by the TH2Gs
under this circumstances.

And this example shows how to disable it again:

sudo ./th2gctrl -n 0 -d
sudo ./th2gctrl -n 1 -d

So to make bezel management effective, you need to add
appropriate th2gctrl commands in some system startup
scripts. BTW.: the settings will persist even when
the PC is turned off but in standby mode. Only a full
power cycle (i.e. disconnect/re-connect the TH2G) will
cause a complete reset.

Here's the full list of command line options the th2gctrl:

Usage: th2gctrl [<options>]*

Options:

-n <num>     device number (default=0)
-l <offset>  left bezel offset (default=0)
-r <offset>  right bezel offset (default=0)
-d           bezel management disabled

Please note that applying the disable option "-d" will
override any provided left/right bezel offset settings.


Bezel Management trough Twinview/Metamodes

Even without any TH2Gs, you can archive bezel management
through special crafted twinview metamodes, so that
you can have bezel management with an nvidia twinview
setup with only two displays. However, this feature is mostly
useful when you have two TH2G boxes (each attached to a DVI
output of a single card) where you have two rows with three
displays, each: for the horizontal bezel management, you
need to use th2gctrl and for the vertical bezel management,
you need to use an appropriate metamode.

Attached to this posting, please find a sample xorg.conf
including a metamode for vertical twinview bezel support.
In this example, the LCD frames between the two LCDs display
rows corresponds to 136 pixel - so the lower 5040x1050 screen
is placed to vertical position 1186 rather then the default
1050. Means, the display is actually 5040x2236 pixel big
rather then 5040x2100, but the 136 pixel in the middle are
hidden.


Propper window maximization for bezel support

Since a number of pixels are hidden under the LCDs frames,
you need to apply an appropriate "TwinViewXineramaInfoOverride"
option in your xorg.conf, or otherwise parts of a maximized
window will end up in a hidden area. In the attached xorg.conf,
the values for this options have been pre-calculated as
an example with the following assumptions: the display
setup consists of two LCDs rows with three displays, each
(2x 3x 1680x1050). Each LCD row is connected to a DVI output
of a video card through a TH2G (two TH2Gs altogether).
So for the left and right screens, you need to subtract 72
(1680-72=1608) and you need to displace the right screen by
72 (2x1680+72=3432). Also, all lower screens need to be
displaced by 136 pixel (1050+136=1186).


Feedback is highly appreciated!

regards

Bernhard

[JaXXoN]

Hi!

please find attached an updated version of th2gctrl. It now supports the
following triple head modes: 5040x1050, 4320x900, 4080x768, 3840x1024
and 3072x768. Also, by default, settings are now applied to all TH2Gs attached
to the PC unless otherwise specified with the "-n" option.

regards

Bernhard


P.S.: this is not strictly related to nvidia graphics cards, but I think it fits pretty
well to this thread :-)

P.P.S: forgotten to mention, compile with "gcc -Wall -O2 -o th2gctrl th2gctrl.c -lusb -lX11"

[laramichaels]

Hello, tripleheaders! Brief question of someone considering spending the lot of money required to get a triplehead2go:

- It is possible to have X "know" that the huge fake screen that the Triplehead2go presents to it really is three screens (in my case, that would be 3 x 1280x1024)?

In other words: is it possible to configure X in such a way that, when you click the "maximize window" button on a given window, it maximizes to cover just the (e.g.) 1280x1024 pixels of the screen in which it is being displayed? (As opposed to maximizing to cover the entire 3 screens!)

[This matters for me a great deal because I have for a long time used a tiling window manager (xmonad) which arranges/"maximizes" windows so that all screen space -- **within the current physical screen** -- is always used up. ]

From what I understand, the way the triplehead2go works could make a nightmare of this kind of behavior. Or is there an easy way to address this?

Many thanks for letting me know your experience with this.

best!

~lara

[JaXXoN]

Originally Posted by laramichaels

- It is possible to have X "know" that the huge fake screen that the Triplehead2go presents to it really is three screens (in my case, that would be 3 x 1280x1024)?

Yes, the nvidia driver has it's own XineramaInfo interface. i.e. when twinview is
enabled, then by default, Xorg reports the two displays to the X clients rather
than just reporting the single big screen. The only difference is that with TH2G,
the nvidia driver can't detect the individual screens automatically and you have
to configure the XineramaInfo manually in your Xorg.conf. For 1280x1024:

Option         "TwinviewXineramaInfo"     "True"
Option         "TwinViewXineramaInfoOverride" "1280x1024+0+0, 1280x1024+1024+0, 1280x1024+2560+0"

regards

Bernhard