3 views with SLI

[Lambis777]

Hello

Have someone try to use 2 VGA cards with SLI connection and to get 3 views?
As far i can see all they use the TripleHead2Go to get the 3 views.

With one VGA we can get 2 views (i have try it and works) BUT i don`t know if we connect and second VGA what will happen ,it will give us the third view?

I ask this before go to buy a second VGA.
Any testings with SLI?

I believe the second VGA to give and extra frames. Right?

Best Regards
Lambis
Greece

[Kennair]

Hi Lambis,

Two things here as far as my investigations have discovered.

1. SLI turns two video cards into one with the combined power of 2. Therefore your system thinks there is only one BIG video card with only 2 video outputs. However, FS isn't designed for SLI (yet) and can't make use of it.

2. If you add a second video card BUT don't enable the SLI mode it will give you the power of 1 video card with 4 outputs. When running with 2 cards, the second card only provides spare outputs, not extra grunt.

So if you are running FS then you can get one BIG video card (say 8800GTX) to run 2 monitors (or 1xTH2GO) and add a second less powerful video card (either PCI-E or PCI depending on your motherboard) and use it's output for the other two screens.

I can tell you though that a TH2GO will give you the extra 3 views from one VGA port with very little impact on your system framerates, whereas using 3 separate VGA ports will cause a bigger hit.

Hope that helps,

Ken.

[Lambis777]

Thank you Ken

I will try to make the second part that you say.

2. If you add a second video card BUT don't enable the SLI mode it will give you the power of 1 video card with 4 outputs. When running with 2 cards, the second card only provides spare outputs, not extra grunt.

both cards must is nvidia or ati ? or can i make combination ?
What have you try and work?
And both card must is PCI - express or can i use one PIC - express and one PCI?


Thank you very much for your help.

Regards
Lambis

[Bob Reed]

With SLI engaged you only get 1 video output. But if you put 2 cards in a SLI capable motherboard you can get 4 video outputs. To run 3 views in FS9 you need a pretty powerful machine but it can be done. I have played with this and it does work.

[Kennair]

Hi Lambis,

It's just as Bob says, if you add two video cards in the SLI video slots but DON'T engage SLI mode, you will essentially get 1 video card with 4 outputs. You can also achieve similar by having 1 powerful card and add a standard PCI card to give you 4 outputs. As I said the main card does all the work, while the second card just acts as spare outputs.

To give you an idea I am running an old system with one AGP video card and one PCI video card. I'm using the TH2GO on one output of the AGP and a single 17"LCD on the second, then a second 17"LCD on one output of the PCI video card. Works great with 3 views and I get 10-20FPS most of the time (with stutters unfortunately, but I can live with that). I would imagine with later model hardware I could achieve very smooth flight.

I would recommend using the same type of video card i.e. both nvidia or both ATI, this just simplifies thing so you don't have to load and configure two video drivers. I know others have mixed nvidia and ATI successfully however. If you intend getting a Matrox TH2GO then you'll need to settle for an nvidia based card, as there are compatibility problems with ATI.

Hope that helps,

Ken.

[Lambis777]

Just make a test with the follow setup:

I use in the PCI - express slot one Nvidia 6600 GT and i get 2 views from here.

And i use in the second PCI - express slot one nvidia 4800 to get the thirth view.

I get 3 views and in full screen mode.
But the frame rate is drop to 10-13 from 20 -22 that i have with one view.
This Is logical i think.

But i notice in the thirth view that i get from the smaller card (4800) the frames are more less than 9
Why this? They need the same good card as is in the first PCI - express slot?

Next week i try a powerfull 8800 GTS with a 6600 together and i see what will happen.
I report here my test.

Regards
Lambis

[Kennair]

Interesting Lambis,

Not sure what you mean by less frame rate on the smaller card? You only get one frame rate for the sim overall. I'm using a 6600 AGP with a 6200 PCI card. As I said, I don't think it matters what the smaller card is, all the work is done by the main card (I stand to be corrected on this technicality however).

Yes your frame rates will drop dramatically the more windows you open. They will also suffer more when running in Full Screen mode. There was an explanation as to why this happens that I read somewhere, something to do with the way windows treats the views, but never-the-less, you get better frame rates when running in windowed mode. However it means having borders around each screen, which doesn't bother me, I'd rather the better framerate.

Keep fiddling and you'll find the best option for your setup.

Ken.

[Lambis777]

Hello again

Finaly i have the 8800 cts and i have make the first test with the fsx.
Also i use a second card 6200 to get the third view.

The slider setting in the fsx is a litle down from the middle.

With only one view i take 60-70 frames.
With 2 views i take 25-30
And with 3 view is the big disappointment ONLY 13-17 frames.

I don`t know if a biger comptuter can help here.
I have an athlon 64 at 3000 with 2 gig of ram.

Also i don`t know if a TH2G card can help in frame rates.

But i read the TH2G it can`t give us 135 dergree of view with zoom factor to 1.00.
And this because as i understand from other posts the TH2G take the front view and distortion the 1 screen to 3 screens.
To get 135 degree of view with the TH2G is to put the zoom factor to ,33 or ,35 BUT this makes all the objects far away and small.
This is not NORMAL view and for this reason the NicD in other forum as i understand it will create 3 new views and place them above the big distortion screen that is unused becuase is not looking good.

But these are 4 views and i don`t know if this reduce the frames.

I don`t know if this problem solved with the TH2G and the 4th view or if someone he find a solution.

I don`t have the TH2G and i can`t make any test with it.

I hope you understand what i try to say becase is very difficult for me to explain it in English.

Please your thoughts and ideas to find a solution and the best configuration for the visual issue with the 3 views.

Best Regards
Lambis
Greece

[Polmer]

I have noticed the same thing;

First of all, my set up;

Asus P5B Deluxe
E6600 Dual Core Duo
NVidia 7950 Main ( main Card) 2 outputs,PCI Express 16x
Nvidia 7600 ( secondary card) 2 outputs,PCI Express 4X mode

With Only one card installed

FSX ~30-40 fps
FS2004 ~30-100fps


With the second card *installed

FSX 8 - 15 fps
FS2004 20 - 30 fps

For me this means if I wish to run multiple monitor outputs from 1 PC
(like a Level D setup) I must pretty much stick with fs2004.

Otherwise, I will have to go the networked route.


In My opinion, FSX & fs2004 don't look that much different from > 4000ft, and fs2004 is absolutely clear ( the mountains look blurry from a distance in fsx).



Polmer


* From my experience, I loose frame rates as soon as I install the second card ( even though I don't use it to display a window).

[AndyT]

When you add a video card, Windows adds extra overhead to control it. This is why you should use the same card, that way you are using the same drivers. It still adds some extra work but not as much.

[James Twomey]

Okay now I'm confused. I thought that purpose of having a SLI capable mother board, with a second video card was to enhance video performance?

I have a quad core mother board with dual video card capabilities and was thinking about putting a second one in. Are you guys suggesting that i should just leave my one video card in for better performance?

[AndyT]

For FSX and Win XP (any version) SLI and Crossfire do not work. If you have Vista and DX10 with the patches, SLI and Crossfire will work but not with FSX. FSX and FS9 were not coded to take advantage of this.

[James Twomey]

Thanks! Well aint that a bummer then!!!

[Lambis777]

With which configuration we can get more frames?

1st) With one big VGA card (give us 2 views) and with a another small VGA (one more view)?

or

2nd) from only one big VGA card and connect the TripleH2G.?

Any test in these 2 configurations? Which have more frames? or not exist any difference?

Lambis

[Prof Bill]

Okay now I'm confused. I thought that purpose of having a SLI capable mother board, with a second video card was to enhance video performance?

I have a quad core mother board with dual video card capabilities and was thinking about putting a second one in. Are you guys suggesting that i should just leave my one video card in for better performance?

I believe that you should also be aware that the Jury is still out on DX10 if you research the Technical Blogs in areas other than FSX but certainly it will of course come good in the fullness of time.

There are two matters that should be considered when upgrading video cards:

(1) In quite a few motherboards you will find that if you insert two (dual) similiar graphics cards in the dual PCIe slots the speed of the Primary PCIe X 16 (PCIEX16_1) slot changes to X 8 mode after you install any device in the Secondary PCIe X 16 (PCIEX16_2) slot.

(2) SLI is not currently supported in FSX.

I have found that the one Graphics Card (Gainward 7950 512MB 1200 X 3800)
at 16X Speed with TripleHead2Go can fully excercise a Q6600 or a Q6700 Quad Core based system. I have tuned for excellent frame rates of 40 to 50FPS.

I would not worry too much about SLI but would concentrate more on "load balancing" in your "quad core" system!
If you do it right you will be more than satisfied!


Bill.

[James Twomey]

Bill,

Thank you! But I do have another question about the Load Sharing that you were discussing. Do you mean load balancing by evenly assigning the work across the 4 CPU's?

[737NUT]

I have a question about DX10. How in the world can we compare DX9 vs DX10 screen shots unless we also have DX10 hardware on our own computers. Make sense?? If i have an old AGP card and winxp w/DX9, i sure am not going to see DX10 stuff in all it's glory. Or am i missing something obvious???

[AndyT]

You MUST have Vista to use DX10.
FSX does not use DX10 to its fullest extent.
You will see some differences but overall, I'd wait for FS-11 for DX10 and full use of multi-core.

[737NUT]

You MUST have Vista to use DX10.
FSX does not use DX10 to its fullest extent.
You will see some differences but overall, I'd wait for FS-11 for DX10 and full use of multi-core.


Thats my point, how can you look at someone else's screenshots showing DX10 if you yourself don't have Vista and DX10 on the computer you are using. I see it on all the forums saying they see no difference, DUHH!! How could they w/o the same new hardware and software. :)

[AndyT]

I know what you mean and frankly, there is no real way to compare them. However, DX10 does look better. I've seen some pix of it and it has more of the smaller details that give realism. Just need to get a nice new machine that will run it.

[737NUT]

I know what you mean and frankly, there is no real way to compare them. However, DX10 does look better. I've seen some pix of it and it has more of the smaller details that give realism. Just need to get a nice new machine that will run it.

I agree 100% I'm waiting till spring to build my new system for vista and DX10. It just frustrates me to see people complain they see no difference when in reality, until they upgrade thier machines, they never will!

[AndyT]

Some people feel the need to complain to be happy. I mostly ignore them.

[Prof Bill]

Bill,

Thank you! But I do have another question about the Load Sharing that you were discussing. Do you mean load balancing by evenly assigning the work across the 4 CPU's?

Hi James,

What I discovered when I experimented with load balancing was that an even workload distribution did not work efficiently. I very laboriously constructed a spreadsheet that allowed me to measure and document the processing efficiency of the Q6600 as I moved processes around. I spent considerable time stripping out redundant processes within the operating system prior to assigning FSX (taking into account where possible what SP1 does with multithreading), needed processes and applications etc. to various processors.

It would have been impossible to mantain control and repeatable configurations without the spreadsheet!
The alternative would be a combinatorial nightmare!!

The way in which multithreading is executed has an effect on repeatable results but nevertheless allows you to generate a semi stable window where results can be generated and usefully utilised.

Eventually you get to a group of configurations where the best description would be that "you have balanced the load distribution on your quad-core"!

I supect and optimistically hope that lots of user friendly tools might emerge eventually that will automate this activity to benefit all!.

Bill.

[James Twomey]

Bill,,

Thank you again. That is very eye opening. I too hope that there will soon be some user freindly tools released. I would really like to capture the full potential of my quad for FSX use.