Nvidia + Matrox TripleHead2Go with resolution 5040x1050!

[JaXXoN]

Hi!

Just for those who might be interested: i figured out how to get the 5040x1050
(3x 1650x1050) wide screen mode working with TH2G on Linux!

Please find attached a sample xorg.conf additionally including modelines for
3840x1024 (3x 1280x1024), 4080x768 (3x 1360x768) and 4320x768 (3x 1440x900).

There is no need to configure the TH2G from a windows computer since
the TH2G does it's best effort to distribute the input signal reasonably.
However, you may like to replace the default 3840x1024 EDID information
flashed into the box, because you may get a very distorted, hard to read
display during boot-up.

ATTENTION: since it is necessary to override the EDID information
(UseEDID set to False and ExactModeTimingsDVI set to True) in the
xorg.conf file, double check that the displays attached are capable of the
desired resolution. In theory, your LCDs could be damaged if they receive signals
beyond their limit! Nowerdays, LCDs typically will just say "Out of Range" on the
on-screen-display and won't be harmed, but you never know. You have been warned!

Make sure that you have the latest firmware installed on the TH2G:
http://www.matrox.com/graphics/en/su...igital/howto1/
You need a windows computer in order to perform the update, but you
can do that within a virtual windows installation inside VMware.

Please note that i needed to increase the 2D clocks for my GTX 260 using
nvidia-settings or otherwise i recognized some annoying screen blanking
during certain graphics operations. I assume that the default memory
bandwidth of 100MHz is probably to slow for the 5040x1050 screen resolution.

regards

Bernhard

[JaXXoN]

BTW.: I have also created an xorg.conf that might do 5040x2100 with six
displays (two TH2Gs with three 1650x1050 LCDs, each).

Because of lack of equipment, i couldn't yet try it out :-(

If somebody has two TH2G and six 1650x1050 LCDs laying
around, i would highly appreciate it if he could try out this setup!

regards

Bernhard

[xianthax]

interesting i am about to try something similar...

i currently have 2 x 8600 GTS cards to 4 x screens at 1680 x 1050 but they can't really keep up with what i need, a fair amount of which is due to some ****e 2d accel performance in QT based apps, 180 drivers were a huge improvement but i still can't stand the fact that i'm video card limited in 2d apps, couple windowed 3d apps and amarok redraws as a slide show. Combined with the Xinerama mouse confusion bug, which triggers more often with higher graphics load and its getting to be obnoxious, but i digress...

i'm curious, why not set this up with 1 screen directly to the card, and 2 tied to the other TH2G to the other output, then use twinview to merge them? This would get around the awkward refresh rate the TH2G gets running 3 screens @ 1680 x 1050. would not allow the 6 screens off 1 car obviously but i'd be very impressed if you could make effective use of 6 screens before being crippled by 2D performance issues anyway....

i have a gtx260 in the mail and will have a triple head 2 go as soon as its back in stock at newegg....going to try a few setups to find the best performance, i'd even be willing to drop to 3 screens if the performance is there, i'm generally limited by 2d performance before i can fill 4 screens with windows anyway...i'll try to post some benchmarks of various setups when the parts arrive.

cheers,

x

[Tub]

Originally Posted by xianthax

i'm curious, why not set this up with 1 screen directly to the card, and 2 tied to the other TH2G to the other output, then use twinview to merge them?

If you search for JaXXoN's older posts, you'll notice that he did that exactly that before. Why he changed, I don't know - he didn't report any trouble and I can't imagine any, either. Maybe just out of curiosity and for the challenge.

JaXXoN, if you'd post a few pictures of your setup for us to drool over, that'd be appreciated

[JaXXoN]

Originally Posted by xianthax

Combined with the Xinerama mouse confusion bug, which triggers more often with higher graphics load and its getting to be obnoxious

By the time i used to have a two card triple-head setup, then i only experienced
the re-draw events while moving windows across screen boundaries. Since i'm
now running my three displays off a single card, i'm not affected, but out of
curiosity, can you please detail this "Xinerama mouse confusion bug"? TIA

Originally Posted by xianthax

i'm curious, why not set this up with 1 screen directly to the card, and 2 tied to the other TH2G to the other output, then use twinview to merge them?

I'm doing exactly that! One 1600x1200 display is straight connected to the
first DVI output of a GTX 260 and the other two 1600x1200 displays are
connected to the TH2G which in turn is connected to the second DVI output
of the GTX 260 which will appear as a 3200x1200 display. So with twinview
it forms a single 4800x1200 framebuffer. In this setup, the TH2G is operating
in dual-head mode, so basically a DualHead2Go would have done it, but the
DH2G has no DVI input. So i opted for the TH2G working in dual head mode.

For details, please check:
http://www.nvnews.net/vbulletin/showthread.php?t=106517

Originally Posted by xianthax

This would get around the awkward refresh rate the TH2G gets running 3 screens @ 1680 x 1050.

Right, the above xorg.conf will do the 3x 1680x1050 in 57 Hz, only!

I have attached a sample xorg.conf that will do the 5040x1050 in a twinview
1680x1050 + 3360x1050 fashion. My 1600x1200 displays can show 1680x1050
(hardware scaled) so i tested this with my setup explained above.

Originally Posted by xianthax

i have a gtx260 in the mail and will have a triple head 2 go as soon as its back in stock at newegg....going to try a few setups to find the best performance, i'd even be willing to drop to 3 screens if the performance is there, i'm generally limited by 2d performance before i can fill 4 screens with windows anyway...i'll try to post some benchmarks of various setups when the parts arrive.

Benchmarks are always welcome! :-)

regards

Bernhard

[JaXXoN]

Originally Posted by Tub

Why he changed, I don't know - he didn't report any trouble and I can't imagine any, either. Maybe just out of curiosity and for the challenge.

Correct! Getting the 5040x1050 mode working with three LCDs off one TH2G
(connected to one DVI output) is a pre-requiste to get 5040x2100 working with
six LCDs off two TH2Gs (connected to the two DVI ouputs of a single card).

Originally Posted by Tub

JaXXoN, if you'd post a few pictures of your setup for us to drool over, that'd be appreciated

Here we go ...

http://qnlx.de/privat/th2g/TH2G_x-plane.jpg
http://qnlx.de/privat/th2g/TH2G_ut2k4.jpg

regards

Bernhard

[JaXXoN]

Originally Posted by xianthax

i'd even be willing to drop to 3 screens if the performance is there, i'm generally limited by 2d performance before i can fill 4 screens with windows anyway.

BTW.: in theory, it should be possible to connect one LCD straight to
the first DVI ouput of a graphics card and the other three LCDs to the
second DVI output via the TH2G box in order to form a 4x1 quad head
(6720x1050) single framebuffer setup with twinview, but i didn't yet tried
that out. 2x2 quad head (3360x2100) would require two TH2Gs (two
DualHead2Go boxes would basically be sufficient if VGA is good enough,
but i can't recall right now if the DH2G can also do 3360x1050)

regards

Bernhard

[xianthax]

i was planning to try out a triple head as you setup first then perhaps get a second TH2G for for the 4th screen, i don't believe my LCDs support 57hz,all depends no how well the gtx260 can keep up with my usage...

the Xinerama bug is here: http://bugs.freedesktop.org/show_bug.cgi?id=18668 for the testing i did for that had 3 screens hooked up to attempt to isolate the bug as initially i wasn't sure if it was a session boundary or gpu boundary issue. thus far it appears to be directly triggered by an animated cursor passing over an X session boundary. Its much more likely to occur as graphics load increases as its more likely the cursor rendering doesn't leave the animated cursor code path before it crosses a boundary.

a common use case for me is winXP in vmware full screen on 1 monitor. 2 windows that are run under wine and are 3d accelerated (pcb/schematic software if i'm working or 2 x eve-online clients if i'm playing) then "support windows" spread about, firefox, pidgin, gkrelln, pdfs, amarok, etc. Not uncommon for me to have mplayer up with a movie on while working as well. Under this load i'm not nearly cpu bound but 2D performance suffers terribly. QT apps like amarok (note: i use gnome not kde) become a complete slide show and firefox scrolls in lock step on some sites (slashdot) and i have to be very careful with added windows, a couple firefox windows and a few pdfs open and the system starts to have intermittent 'hangs' meaning the screen locks up for a few seconds but the processes are not locked up, its purely graphical.

it also appears that with this setup performance degrades over time, after a while i could close almost everything and mplayer can't manage to play a movie without stuttering or occasionally playing in a pulse like manor, i.e. the framerate isn't constant but "wobbles" tho the audio doesn't resulting in desync, etc. closing everything but mplayer or even restarting mplayer does not fix this. I have to reboot X.

my usage is odd in that i tend to run a couple apps using 3d/opengl that aren't terribly stressful by modern standards and a ton that are 2d only and not using opengl.

180.22 has improved the situation to what i described above, with 177 i couldn't get away with half as many windows open..

cheers,

x

[JaXXoN]

Originally Posted by xianthax

i don't believe my LCDs support 57hz

I guess most LCDs support 57 Hz, but YMMV ...

BTW.: i was told the 57Hz has drawbacks for video playback (stuttering,
skipped frames), but i guess that only applies to HD content (30Hz)?!
Is somebody aware of any further implications when using 57 Hz?

Concerning system performance/stability: maybe you are facing some
sort of incompatibility or broken hardware? For example i once had a
GF5950 that always took 70% of the CPU cycles (looping the nvidia
interrupt service routine), even when the machine was otherwise idle.
Replaced it by another GF and everything was fine, again.

regards

Bernhard

[xianthax]

its possible, tho its not obvious, i'm not experiencing any weird cpu spikes.

perhaps the only odd thing i've noticed is the 8600's run hotter than i would like, couple 3d apps and they can hit 73C and idle @ 60C. I doubt this is case cooling related, while the case is "full" the cpu hits around 62C with cpu burn running on all 4 cores for several hours, never gets more than 55C or so real world usage and 48C @ idle. perhaps xinerama in general puts a lot of strain on the cards. i've wondered on exactly how the work load is split up because loading up one card with a ton of windows and apps definitely effects the rendering performance of the other card.

for reference:

MB: asa p5e ws
Q6600 quad @ 3.2ghz
4gb ram
2 x 8600 gts (xfi maybe? don't remember brand)
3ware 9550 pci-x, 4 drives in raid5 mounted @ /home
130GB WD raptor mounted @ /
2 x 250GB WD drives raid1 encrypted data
supermicro 4u/tower server chassis

i wouldn't think the refresh rate of the LCD should have much effect on video playback....even "30Hz" (NTSC) is really 29.976fps while film is 23.976, none of the common rates divide evenly into 60 anyway. Refresh rates under 60 in general, can cause headaches and such in some people.

cheers,

x

[JaXXoN]

Originally Posted by xianthax

they can hit 73C and idle @ 60C.

Not too bad! My former 7800GTXs and 8800GTs easily hit 90C
(plenty of full steam running fans in the case). The GTX 260
behaves a little bit better in this respect.

Originally Posted by xianthax

i wouldn't think the refresh rate of the LCD should have much effect on video playback....even "30Hz" (NTSC) is really 29.976fps while film is 23.976, none of the common rates divide evenly into 60 anyway.

I was told that 57Hz would be bad for video playback, but since i don't watch
videos on my PC, i don't care anyway :-)

Originally Posted by xianthax

Refresh rates under 60 in general, can cause headaches and such in some people.

AFAIK, this was true for CRTs (50Hz PAL vs 60Hz NTSC), but LCDs shouldn't be
affected any more ... also, even with CRTs @ 57Hz, i wouldn't expect a lot of
headache :-)

BTW.: when i was young, i used to sit for hours in front of an aging
B&W TV donated from my grandmother at least a year or so
operating a good old C64 before i got an upgrade to a used
color TV - but this was still 50Hz PAL (located in Germany).
Never had any headache because of the TV :-)

regards

Bernhard

[JaXXoN]

Hi!

Just to keep anybody who is curious in the loop: today i purchased a second
TH2G and the xorg.conf for 5040x2100 posted above (post #2) worked out
of the box!

However, i currently have only three LCDs so i could only see three
out of the six tiles at any given time, but i would now bet my a** off that
it will work with six displays!

regards

Bernhard