It is currently Mon Feb 17, 2020 2:11 am

Reply to topic  [ 5 posts ] 
 3D split SLI for compatibility? 
Author Message
One Eyed Hopeful
User avatar

Joined: Sat May 12, 2007 1:09 pm
Posts: 20
Reply with quote
Greetings all.
I'm a Stereo enthusiast... well, sort of, since I nearly gave up with stereo gaming, due to too many driver issues (and a slow pc).
Now, I could plan for an upgrade, but I think I'm not the only one wandering if it's still worth the effort and expenses involved.

There's one thing I keep asking myself, one that could make or break it, since I can't imagine the stereo driver development in its present form to improve significantly in the near future: too many configurations, new graphic techniques like HDR, Vista issues...
We can't accept buying cutting edge PCs just to be forced to wait a full year just to be able to play a game like it's still DX8 era, plus visual artifacts, erratic behaviors, plus low fps.

So, here is my question: is it possible to develop a stereo driver that uses 2 cards in SLI to essentially generate separate renderings for each eye, getting the same performance of a single card without stereoscopy?
This way, could we possibly get HDR + the desired amount of AA and TRAA (I know it's less important in 3d, but still...), aniso, motion blur, depth of field, any render to target effect...?

After all, if going stereo means deactivating any new fancy graphic technology... this is becoming less and less acceptable. On the other hand, imagine the jungle in Crysis with 3D shadows and light rays... 8)

I understand it's not that simple to get a default-to-SLEYES driver (I just made it up, it stands for SLI dedicated to separate eyes) because the programmers of the game assume that the perspective the game creates corresponds to your position and FOV, while adding a second card dedicated to a second view would shift you sideways in the virtual world, so you can't just create 2 views, but you should add a software layer that keeps the centered FOV for general purposes like targeting, and then lets the cards calculate 2 shifted views. I guess this could generate some trouble depending on what the programmers meant the graphic card to do...
But then I think (and hope) we'd still get a gazillion times more stable and compatible driver, making SLI stereo PCs (+projector or planar setup, + simple, effective in-driver game presets) a viable solution for anyone going for the ultimate experience, not just s novelty for a hardened minority.

So, is there anyone competent who's willing to enlight me?

Bear in mind that the answer to this question is of fundamental importance for anyone like me who's starting to plan his next pc buy: going for a SLI rig ready for ultimate stereo? Going for excess graphics and abandoning any stereoscopy dream? Going for an intermediate solution, nothing fancy, forgetting about HDR, still struggling to get some barely playable stereo games, playing so-so 2D games most of the time?

Sat May 12, 2007 2:20 pm
One Eyed Hopeful

Joined: Thu May 03, 2007 4:02 pm
Posts: 17
Reply with quote
Post Yes
To answer your questions : SLI : no. No SLI because SLI is about as cantankerous for games as 3d is. You need "profiles", and people complain of frequent crashes, graphical glitches, and instability. Sound familar? Except with SLI you don't get the incredible image 3d gives : you just get maybe 50% more frames per second. As far as I know, nvidia has never even considered 3d SLI drivers.

Get a good single card solution. 8800 640mb is the only option for the next 6 months. (forget ATI, and nvidias next cards will be too expensive for the next 6 months. You DO need the 640mb because current games can already use 500mb)

So there, I pretty much eliminated all the uncertainty about the graphics card. XFX offers a "double lifetime" warranty, so it is a good choice because if you really want the ultimate in graphics, you'll need to upgrade in 6 months.

Nvidia single cards do work in 3d, and eventually might even do so reliably. Maybe.

This is the way to go. That, or support built right into DirectX for multiviewpoint friendly rendering. Microsoft has refused to support stereo in DirectX 10. (so much for the "advanced, revolutionary features". The idiots : stereo is one way that PCs can beat consoles)

Alas, as it is right now I would try to come up with a system that worked well in 2d. Perhaps : if you really wanted an ultimate setup, you could build a planar mirror system that could be UNPACKED into a dual display setup. Umm, right now I don't have a design for one, but I'm sure it is possible.


I sort of have the same dilemna : I have a 52" LCoS HDTV for my primary computer display. The quality is about the best 2d display quality possible with current technology : a huge, sharp, very high brightness image.

However, I have found that MOST games, even current ones, do work in 3d. They may have glitches, and usually something has to be disabled. The very latest games (oblivion) leave me stuck in a dilemna : my 7900GS CAN play it in 3d, but it doesn't have enough power. 8800 3d drivers are not good enough, yet.

So I pretty much have both solutions : I use the 52" TV for 2d games and web browsing, and I switch over to the planar mirror setup for 3d. VERY PRICEY - the 3d setup costs $650, while the HDTV is $1400. It does give me the best possible displays, pretty much, though it is annoying having to switch back and forth.

I have found a way to get around most of the annoyances with software : I have a separate OS partition I use for 3d games, and I frequently make backups. That way, once I finally do get a game to run in 3d I can save a disk image of what I did to make it work.

Out of about 40 games I have, the top games of the last 3 years, I have gotten about 35 of them to work in acceptable 3d. I'm compiling a list, and what I did exactly to make each of them work well, as we speak.

Wed May 16, 2007 2:40 am
One Eyed Hopeful
User avatar

Joined: Sat May 12, 2007 1:09 pm
Posts: 20
Reply with quote
Your answer (which I appreciate) is very saddening.
I'm not a teenager anymore, who wants the inconveniences of 2 expensive and bulky monitors, 2 partitions, lots of tweaks to be done, waiting so many months for a driver without being sure you made the right hardware choice...
Then you get a subpar performance anyway.
Things need to change.

As for the subject of the thread, I never tried SLI but I'm not surprised it's buggy.
Now, since SLI and stereoscopy are just a novelty for a handful of enthusiasts, of course Nvidia gives them low priority, so they are less polished, you get the picture.
But the advantage of making the stereo driver a major selling point for SLI, giving a 3D game experience ATI can't possibly offer, is way more rewarding than spending a little less on developing buggy stereo drivers.

It's a market where people are willing to spend more, but are forced to buy a last generation card instead of 2 cutting edge ones!
So Nvidia is missing a chance.
And giving people a reliable, fast solution without loss in image effects, this stereo market could grow a lot!

But the issue here was the feasibility of a StereoSLI driver, meant to bypass many of the incompatibilities of today's drivers.

My point is that hardware and drivers are designed to do something that is indeed natural: 1 graphic card creates 1 virtual image.

The problem with Stereodriver is that it's forcing the hardware to do something awkward: use just 1 card to generate 2 images.

The problem with SLI is that it's forcing the hardware to do something awkward: use 2 cards to generate just 1 image.

But a StereoSLI would do something again conceptually much simpler: use 2 cards to generate 2 images!
That's where I think lies the inherent aptitude of SLI for stereovision. The possible basis for drivers which can be developed in less time, but very reliable indeed.

Fri May 25, 2007 9:03 am
3D Angel Eyes (Moderator)
User avatar

Joined: Wed Dec 31, 1969 6:00 pm
Posts: 5749
Reply with quote
Did you look at the screenshots in the NEWS section?


Fri May 25, 2007 9:18 am
Profile WWW
One Eyed Hopeful
User avatar

Joined: Sat May 12, 2007 1:09 pm
Posts: 20
Reply with quote
Those screenshots are very good.
I was hoping the big announcement coming soon was indeed about a SLIstereo driver (so that you were using a NDA-protected :D version): this would be not only beneficial to everyone who wants stereovision to succed, but it would also mean (if I am correct) that future drivers will be more stable without so much work, i.e. the need to wait months.
In fact, if a driver needs to be specifically conceived to bring stereo with a single card, for each step forward you need to reprogram a DX9 XP version, a G80+ XP, a DX9 Vista version, a DX10 Vista version, a DX10 Vista 64 bit version, and maybe more...
While a SLI version would be easily derived from the vanilla drivers, at least that's what I hope...

Mon May 28, 2007 8:36 am
Display posts from previous:  Sort by  
Reply to topic   [ 5 posts ] 

Who is online

Users browsing this forum: No registered users and 4 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
Designed by STSoftware.