My dream on four monitors?

I asked about this a long time ago, told it was "being worked on" but saw no result...

Maybe the idea of DreamScene + dual videocards (NOT CrossFire/SLI) will get some new attention.

Using two video cards in a seperated format instead of a SLI sort of set up? I'm at home and I don't have anything to test with here. However I am curious if you use any software for that set up?

I have a rather high-end system.  Specs are below.
CPU: Q6600 @ 3.2GHz (Intel, obviously)
RAM: 8GB DDR2-800MHz 5-6-6-18 OCZ Vista Upgrade
GPU1: NVIDIA 9800GX2 in Dual-GPU mode
GPU2: NVIDIA 7900GTX
HDD1: Western Digital Raptor 150GB 10k RPM
HDD2: Western Digital Caviar 750GB
HDD3: Western Digital Caviar 750GB
HDD4: Western Digital Caviar 120GB PATA
OS: Windows Vista Ultimate x64 Service Pack 1 w/lastest Windows Updates
MON1: Acer AL2216BW 22" @ 1680x1050
MON2: Acer AL2216BW 22" @ 1680x1050 (I upgraded since my last thread on the subject).

There are actually *three* physical GPUs inside my system.  However, two of them (inside the 9800GX2) are seen as a single device by CUDA (NVIDIA C-based programming language) and, apparently, by DeskScapes/DreamScene as well. 

If the 9800GX2 is...
...in Multi-Monitor Mode (no SLI), DeskScapes works fine on ONE monitor, but not both regardless of whether the second screen is attached to the 9800GX2's second DVI or a DVI on the 7900GTX).
...in Multi-GPU Mode (SLI-on-a-stick), DeskScapes works fine on ONE monitor.  If a second monitor is attached (which for me is normal) to the 7900GTX, DeskScapes and DreamScene will NOT run.

DeskScapes does not allow using more than one video adapter (unless it's masked into one the way Dual-GPU mode is on the GX2).  Period.  Even two monitors on the GX2 cause problems, since that is actually two adapters in one, each with a single DVI port.

What I'm asking for (and also this other poster as well) is for DeskScapes to function if more than one "graphics device" is found (regardless of whether it's SLI-on-a-stick or just a plain Jane graphics card, as DeskScapes doesn't seem to have a problem with dual-GPU boards).  In my case it is because I want games on one monitor (9800GX2), desktop stuff on the other (7900GTX).  In the original poster's case it is because he wants four monitors but lacking a TripleHead2Go or similar, he cannot run all those displays from a single card.  In both cases there are only two "graphics adapters" to be concerned with as DeskScapes sees an SLI set as a single card (even if it's SLI on a card).  Thus, the problem is not with SLI or CrossFire.  The problem is a limitation on the number of graphics adapters (from what I've seen).

I use UltraMon to enable a taskbar on the second monitor.  Things like Windows Sidebar, RocketDock, iTunes, Hamachi, Trillian, Xfire, Folding @ Home SMP and Trillian run on my other screen while I do work/play on my main monitor.

Thank you for taking the time to look into this again.

Yes, I also have a similar setup and would like to be able to play Dreams on more than just the primary adapter's two monitors (which are just clones of one another).  I'm that whatever fix allows us to to stream to two cards would also allow us to stream different dreams to different monitors.

Note that this wasn't really possible under XP due to the multimonitor GPU acceleration bugs (only one monitor was GPU accelerated at a time) and the lack of separate threading for XP directshow codecs (playing two MPEG2 streams would collide with each other for resources for example).

But under Windows Vista, both of these issues were resolved (as I have tested for both nVidia and Microsoft and you can test yourself by playing two videos at the same time), so there is no reason that two or more streams can be piped to differing monitors.  Since the GPU hit is neglible for video acceleration on modern machines, the only price you'd pay is via the CPU.  And on any dual or quad core system, that CPU hit remains neglible.

My expectation is that it would take more time to develop a simple interface to select this dream for that monitor than to actually get this screen selection working (as Stardock already has applications like ObjectDock that can ID which monitor you want to play on, etc.)

I hope my notes help in some way to somebody.  Lack of real multi-monitor support is the only thing keeping me from running dreams on my primary system 24/7.

 

 

For technical reasons you can only use one adapter as supporting multiple adapters would come at a considerable memory and cpu cost.  This is especially true for videos where you would end up having to decode the video using cpu only which even on a dual core machine would use very high levels of cpu (probably over a single cores worth)

Is there at least a way to get DreamScene to run on one monitor even if multiple display adapters are detected then (i.e. "Pick which monitor you want your Dream on")?  Or is anyone using multiple monitors and multiple display adapters out of luck?

How hard is it to decoded a video frame once and copy it to every monitor?  Can'y you copy a video frame from one of the video card's memory?

I do find it interesting because Seabass told me at one point in my own thread about this very topic that something was being worked on and that I could expect something (a yea or a nay) around the time that DeskScapes 2.0 was released (since DeskScapes 2.0 was taking up all the development resources at the time).

Neil, without breaking my NDAs, I can say that right now, I'm using multiple GPUs to play and accelerate multiple simultaneous hi-def video streams on dual and quad core machines under Vista.  As long as each stream is piped to a different adapter, and you have one codec PER stream (which is a player thread issue), this approach scales linearly by GPU and CPU.  The only thing I can't do is make them desktop wallpaper dreams cause this project doesn't need that coded and I'm not really looking to get into the software business. 

But, because these data streams are already MPG2 compressed (and assuming you cache the whole video in RAM, which makes the most sense in these days of 4 gb systems), one could do something similar to the DLP software players like...

http://www.3dtv.at/Index_en.aspx

This software can read two video streams, interleave them in real-time (for the DLP matrixing) and play the result across 2 monitors per adapter, etc.  I'm sure your comments are 100% accurate for Windows XP, but I do believe Vista has addressed these issues at the core level.

Regardless, as a layman's example, I just played 3 1080p streams on my 3 monitor/2 adapter system.  To get around the windows media player restriction of having one instance open at a time, I played one 1080p source with VLC on monitor 1 (adapter 1 primary), another on windows media player classic on monitor 2 (adapter 1 secondary), and a third playing in Vista's latest Windows media player on monitor 3 (adapter 2 secondary).  This is a quad core 6600 and each video is playing off a different drive.  I can't cache them to ram because I chose full length movie sources for the test.  All three played at full speed, sound mixed for all three, etc.  CPU hit was heavy, but these are all MP4s at 1080p, and using three different players makes this HARDLY the ideal configuration, hahaha.

As a second layman's example, I just played two instances of VLC in DirectX "Desktop Wallpaper" mode, one on monitor 1 (adapter 1, primary) and the other on monitor 3 (adapter 2, primary) and again both were playing CPU intensive mp4's at 1080p in realtime with sound streams.  Again, the CPU hit was higher due to MP4s at 1080p, but there were no dropped frames, etc.  MPG2 files have shown great GPU acceleration offloading compared to mp4.

And finally, you are probably already aware that DX11 will support multithreading within the GPU, so that would address this on a single GPU as well.  So all of this should be even easier under Windows 7/DX11 next year.

I hope some of this info helps, even if it still means we can't have this feature any time soon.  Thanks for all your excellent work so far on all the cool toys we all love so much.