P3D V3, Nvidia surround and SLI

[Jessica Bannister-Pearce 120]

Hey guys,

 

So, this morning I've been installing a second 680 gtx in my machine to give it a bit of a boost. (The cost of the 980 it is just out of my reach at the minute, hence the second 680).

 

anyhow, I set everything up and loaded up P3D with Nvidia surround running on my three screens with a resolution of 6000 X 1080. I used Nvidia inspector to monitor the gpu usage, and sure enough, both cards spooled up to full. However, I didn't see any appreciable increase in Fps, and loading in a bit of weather and fog, the Fps dropped just like it did with the single card. Performance remained the same as a single card all through testing.

 

So figuring I should be seeing an increase, even if it's just a modest one, I played around with the Nvidia control panel. Switching from surround to maximum performance though changed things a bit. Now using my three monitors as three monitors, not in surround, but spanning p3d across them, suddenly SLI starts showing a great Fps increase and in heavy weather things are much better. Of course the downside is i don't have any bezel correction.

 

So my question is, what, if anything am I doing wrong? Is there a way to use surround and get the SLI boost, or is it just a case of 'suck it up'?

 

Best wishes,

Jess B

[Poppet 709]

*Bump*

 

I cant help you.  But loads of folks here use Sli with good results

 

Can Jessica please get some help here  :smile:   

[Manny 1,293]

The general theme here is with better video card or with SLI you are not going to get more FPS, but you maybe able to fly in lot more clouds and bad weather or higher AA settings ..since those are work done by the card.

[vgbaron 3,620]

Jessica - TMK the Nvidia Surround does not support the bezel correction, or at least they didn't. If anyone has later info, they will post I hope.

 

Vic

[SirStiggie 63]

I do have SLI but currently only run 1 4K monitor with my cards (980 Ti). I don't get significantly more FPS than I did in 2.5. What I do get is a significantly smoother experience with none of the artifacts and crashes I had with 2.5. For example, at FSDT KFLL with heavy clouds and some traffic in the PMDG 777, I am in the high 20's to low 30's. This is with higher settings than I had in 2.5.

 

From monitoring with MSI afterburner, I do see P3D using both cards significantly harder than 2.5 did. I've seen on other forums posts with significantly better FPS than 2.5. I have not seen that, just an overall better experience using SLI than I had with 2.5. Please note I have not done any tweaking/tuning with nVidia Inspector though.

[Slayer 190]

You need a really strong CPU to take advantage of SLI. If your CPU is loaded down with autogen and traffic or just simply can't keep up the net increase of FPS will be negligible. It's just simply that the CPU can't feed the beast. 

 

The benefit you can still get is higher AA etc , without a performance loss compared to a single card. The other issue you may be running into is that in SLI mode graphic memory is used in parallel . So: a 2 GB 680 SLI setup doesn't = 4 GB of graphic memory available , it's still 2GB.  BUT if you do not run the cards in SLI you can technically use 4GB of video memory (this is an example I don't remember the exact memory of the 680). This is very critical when you have such an extreme resolution of 6000 X 1080 because each card is only pushing the resolution of the screens connected to it.. I have a feeling your 2 GB of video memory is exhausted just on the resolution alone.

 

I know it's not what you want to hear but I had SLI 680 then went to a 6GB Titan because of this ( more for X-Plane than FSX / P3D)

 

Edit: There is only Bezel correction with spanned displays I believe. running 3 separate displays will not allow it.

[Jessica Bannister-Pearce 120]

Hey guys, thanks for the answers, though I'm not sure I explained my issues correctly.

 

Normally I drive my three screens with a single 680 gtx via Nvidia surround. That's all good.

 

However with sli switched on, I'm seeing both cards running at full power in surround, but only the single card is actually making a difference.

 

Swapping to 'maximum performance settings' switches from surround to using the three monitors as three monitors (not one large screen as in surround). And SLi works correctly. Both cards work in sync, I see a performance increase and flying into clouds and fog is much better.

 

A little more reading last night turned up that it may be a driver issue. Lots of people saw surround and sli working properly with their old sandybrige setups, only to see it not work once they upgraded to Haswell. Since i have a 4770k, I'm wondering if the bug is still around.

 

So just to clarify, in surround, both cards are running full blast, no performance increase.

Maximum performance settings. The cards work as expected, sli is fine.

 

For now I'm just going to live with it. This is just a stop gap until I build a new machine next year. I'm moving home in the next few months, so money is tied up there. :(

 

Best wishes,

Jess B

[Slayer 190]

Some people have that issue, especially in Windows 8 / 8.1 , but some on Windows 7 as well

 

You'll probably find that if you run 3dmark or another benchmark tool that it's not just P3D that's affected it's all 3D games. No one that I ever saw have this problem ever posted a solution unfortunately. Some suggested it's because of using an analogue connection on 1 of the ports or adapters to an old VGA display or some such but not everyone who had the issue used an analogue connector either.

 

Just one of those mystery things I guess