Stepping up to the LM hack and enabling SLI compatibility has been truly amazing. Adding AffinityMask=1364 for my rig added the icing to the cake. Very well worth aspiring to.

 

This thread tells how to apply the hack.

 

http://www.prepar3d.com/forum-5/?mingleforumaction=viewtopic&t=6352

 

Mac

What sort of benefit are you seeing?

I can confirm as well that there is a pretty significant performance increase. My frames almost doubled at KSEA with the PNW scenery. The bad news is that this only occured when I selected maximize 3d performance in the nvidia SLI configuration. If I activate all displays, but only have the sim on one display the second GPU doesn't get used at all. More testing is needed. I want to make sure my config is intact, but initial results look promising.

 

I have two GTX 680 classifieds.

I am keenly interested in this too... i have 2 x GTX670 OC cards in SLI and have my 2 27" monitors linked as one using a Zotac splitter then 2 18" below them for pop up gauges etc... works well...

 

I have all my monitors plugged into the one card at this point...

 

I am using the tweak as listed above to get this working...

 

Looking forward to more testing results!

I am not the best person to get involved in the fine technical detail, but I have two monitors plugged into one GPU and I have used the "Maximise 3D Performance" in the NVIDIA Control Panel. I usually fly using a main 22" TV monitor and "other windows" on the side monitor.

 

I agree with Scott, my FPS at least doubled which allowed me to move the sliders to the right. I also run 50% AI Traffic. Very dense scenery areas like Orbx Melbourne pull the FPS below 20 in some places.

 

Looking foward to a NVIDIA listing for P3D v2.2 now, but I am not brave enought to experiment without directions from a wiser person.

 

Mac

So at KSEA with Global and PNW scenery, UT2 at 50%....I am pretty much getting almost double frames with SLI enabled in most weather conditions on a single display. Are you guys getting the same results? I want to reiterate that this is only when "Maximize 3D performance" is selected. 

 

When spanning across my three 27 IPS displays in surround mode, I take a significant performance hit, which is to be expected. 

Would it work with a 3 monitor setup in 2d NV Surround, or only with 2 cards connected to 1 monitor ?

It should work with three monitors on the master card.  No need to connect anything to the other card.

I used this and saw about a 50% increase in frame rates using a GTX 590 on my single monitor.  There were a few graphical anomalies, but as Beau explained in the Lockheed forum, certain effects persist frame to frame, so using Alternate Frame Rendering (the method of SLI this hack uses) breaks some things; some issues were to be expected.  

 

I'm very excited to hear how close full SLI support and optimization are, and to see what two high VRAM GPU's will be able to push through the sim.

I'm not sure VRAM is going to matter yet, not until the 64bit hurdle has been crossed.  For most people who are not pushing past 3 fullHD monitors or a 4k monitor it won't matter.  I've been monitoring 3 fullHD screens in many games now and memory has not been an issue.  3GB is just enough.  There may be some limitations, there are some reports of extreme cases going to 3.5GB usage on Titans, but again, very large viewing demands.  And that was a year ago when I researched the issue, before some of the driver updates.  There is no need to go to 6 at this time.  

Would it work with a 3 monitor setup in 2d NV Surround, or only with 2 cards connected to 1 monitor ?

 

So I have three 27 inch IPS displays. The first one(middle) is connected to GTX 6801. The other two(left monitor and right monitor) are connected to GTX6802. I will try connecting all three monitors to one card in the morning to see how things go. 

 

When running in surround, both of my GTX680 classifieds are almost maxed out on CPU. When running on a single display in 3d performance mode, both cards are running around roughly 40-50% and that mode is where I am seeing the real performance benefits(almost double my non SLI single monitor configuration). 

So I have three 27 inch IPS displays. The first one(middle) is connected to GTX 6801. The other two(left monitor and right monitor) are connected to GTX6802. I will try connecting all three monitors to one card in the morning to see how things go.

 

When running in surround, both of my GTX680 classifieds are almost maxed out on CPU. When running on a single display in 3d performance mode, both cards are running around roughly 40-50% and that mode is where I am seeing the real performance benefits(almost double my non SLI single monitor configuration).

Thanks.

 

In FSX one can benefit from SLI and NV 2d surround in spotplane view and 2d cockpit view ( without gauges )

Actually, the middle monitor to the primary, and the sides to the secondary is the way it used to be.  But I don't see any reason why SLI won't work with all connected to one.  In fact you could have up to six on there.  Maybe 7 if you have a port on the board.  Thanks for the interesting info on your SLI test.  That's in Prepar3d 2.2?  Nice.

So I have three 27 inch IPS displays. The first one(middle) is connected to GTX 6801. The other two(left monitor and right monitor) are connected to GTX6802. I will try connecting all three monitors to one card in the morning to see how things go.

 

You guys might be out of luck here.

 

According to nVidia in a Surround SLI setup one monitor must be connected to the second video card.

 

http://www.geforce.com/whats-new/guides/how-to-correctly-configure-geforce-gtx-680-surround#3

 

Ok this is for the 6oo series but I assume it to be the same for all cards.

 

gb.

 

 

Actually, the middle monitor to the primary, and the sides to the secondary is the way it used to be. But I don't see any reason why SLI won't work with all connected to one. In fact you could have up to six on there. Maybe 7 if you have a port on the board

 

AFAIK...

The maximum number of monitors you can connect to any nVidia surround setup, SLI or otherwise, is four, (3+1).

The maximum number of monitors you can connect to a non-surround SLI setup is two, unless you add another card, with special conditions.

See here:

http://www.geforce.com/hardware/technology/sli/faq#s1

 

gb.