nVidia 375.70 causes FX to flicker when in SLI performance mode.

[angeli662 43]

Same flickering effects here with SLI. I also tried turning off HDR and still had it. Definitely driver related. I rolled back to 373.06. I really thought I saw some performance improvements in the new 375.70 driver.  

 

I'm with Rob, I hope Nvidia fixes the SLI issue, we all doubled down on the video card investment and hope the SLI will have a path forward for P3D.

 

EDIT: I am running P3D 3.3.5 and 2 980GTXs on Win7 64bit.

Have you tried the nvidia hot fix 375.76?

 

http://nvidia.custhelp.com/app/answers/detail/a_id/4250

[TheFlightSimGuy 514]

I guess the SLI market is just too small and doesn't justify nVidia's resources or maybe it conflicts with VR (which doesn't support SLI, or more accurately doesn't utilize SLI) and/or their "Shield" plans.  Either way, it seems SLI (even 2-way) at the driver level is slowly being dropped and not supported.  It's interesting that nVidia seem keen to sell SLI for 10 series with their new "SLI bridge" design, but don't have plans to support it.

 

I'm keen to see if nVidia do fix this SLI issue (without just disabling SLI in the profile), if not, then I guess the writing is on the wall for SLI.  SLI really helped me enjoy AS16+ASCA to it's fullest, but without SLI my framerate takes a huge hit with AS16 on a stormy day (back to 3 layers and 80mi rather than 5 layers and 110mi).

 

So you are saying that this is a Nvidia issue and not a compatibility issue between P3D and SLI drivers specifically? Because every other AAA game I play right now, from BF1, The Division, to COD Infinite Warfare, to Titanfall all benefit from SLI. I don't think it is a "SLI is dying" issue, I just think its is driver specific compatibility with P3D specifically. 

[supersym 52]

The same for me.

Did you try the last hotfix ?

With a clean installation no more issue with the hotfix 375.76 

[FlightSimDimm 16]

 

 

With a clean installation no more issue with the hotfix 375.76 

 

So no more SLI flickers of the FX contrails? Has anyone else confirmed?

[TheFlightSimGuy 514]

So no more SLI flickers of the FX contrails? Has anyone else confirmed?

 

I did a clean install of both P3D and the new drivers, still flickering.

[Guest]

Curious, where are you getting the drivers from?  (link)?  

 

They don't appear to show up at my "normal" spot for downloading beta drivers which is here.

 

Cheers, Rob.

[supersym 52]

I took it here :

 

http://forums.guru3d.com/showthread.php?t=410729

 

but ilt may be dependant the config...

[angeli662 43]

Curious, where are you getting the drivers from?  (link)?  

 

They don't appear to show up at my "normal" spot for downloading beta drivers which is here.

 

Cheers, Rob.

Rob if you go to the Nvidia site and type hot fix in the search bar it will take to the 375.76 driver.

http://www.nvidia.com/object/nv_search_us.html?cx=009029091075083507105%3A9leknaf7r_8&cof=FORID%3A11%3BNB%3A1&ie=UTF-8&hl=en&gl=us&q=hot+fix

[supersym 52]

in fact I've still a few flickering with a longer fly I did yesteday evening.

less but still a few...

[Mickeyj 35]

Hi there,

 

did anyone try to use the Killing Floor2 SLI Profile? That helped me with flickering FSTramp.

[Cruachan 705]

It's interesting that nVidia seem keen to sell SLI for 10 series with their new "SLI bridge" design, but don't have plans to support it.

 

Hi Rob,

 

I was interested to read your speculations regarding nVidia's current attitude towards SLI. I have to say that this does seem rather unlikely as long as there are single GPU units incapable of outclassing the performance (impressive as they are these days) of those configured in SLI. The market may be somewhat restricted, but it is there nonetheless and nVidia will always want to encourage sales. My own experience of SLI in P3D is very good - it was a long time coming but certainly worth the wait. Yes, some issues have surfaced recently, but hasn't that always been the case with some driver sets? I would hope, at least for the foreseeable future, that nVidia wouldn't turn there backs on proven technology that, in the right circumstances, can make such a difference to our experience, whether it be in gaming, flight simulation or, indeed, scientific and engineering applications.

 

Regards,

Mike

[Guest]

The market may be somewhat restricted, but it is there nonetheless and nVidia will always want to encourage sales

 

Hi Mike, there are several factors that I think have influenced nVidia's drop in SLI support/resources

 

1.  3-4 way SLI is extremely rare so investing engineering resources is costly and is not being supported in newer GPUs

2.  2 way SLI is also very small market segment so it's getting less engineering resources and as we've seen nVidia are having problems making it work in all cases

3.  DX12 allows for developers to address multiple GPUs removing nVidia from having to adjust drivers/profiles for specific titles

4.  VR SLI implementation increases complexity (VRWorks API)

 

Although SLI has the word "scalable" there appears to be some engineering costs associated with keeping the "scalable" aspect working in more than 2 GPUs.  There are also issues around Vsync and Triple buffereing for certain modes of SLI.  Wiki has a good article on SLI here that provides a good overview of some of the challenges and expectations taking note of Caveats:

 

 

 

• Not all motherboards with multiple PCI-Express x16 slots support SLI. Recent motherboards as of May 2016 that support it are Intel's Z and X series chipsets (Z68, Z77, Z87, Z97, Z170, X79 and X99) and AMD's 990FX chipset.^[16] Aside from a few exceptions, older motherboards needed certain models of nForce chipsets to support SLI.
• In an SLI configuration, cards can be of mixed manufacturers, card model names, BIOS revisions or clock speeds. However, they must be of the same GPU series (e.g. 8600, 8800) and GPU model name (e.g. GT, GTS, GTX).^[17] There are rare exceptions for "mixed SLI" configurations on some cards that only have a matching core codename (e.g. G70, G73, G80, etc.), but this is otherwise not possible, and only happens when two matched cards differ only very slightly, an example being a differing amount of video memory, stream processors, or clockspeed. In this case, the slower/lesser card becomes dominant, and the other card matches. Another exception is the GTS 250, which can be paired with the 9800 GTX+, as the GTS 250 GPU is a rebadged 9800 GTX+ GPU.
• In cases where two cards are not identical, the faster card – or the card with more memory - will run at the speed of the slower card or disable its additional memory. (Note that while the FAQ still claims different memory size support, the support has been removed since revision 100.xx of NVIDIA's Forceware driver suite.)^[17]
• SLI does not always give a performance benefit – in some extreme cases, it can lower the frame rate due to the particulars of an application's coding.^[18] This is also true for AMD's CrossFire, as the problem is inherent in multi-GPU systems. This is often witnessed when running an application at low resolutions.
• Vsync + Triple buffering is not supported in some cases in SLI AFR mode.
• Users having a Hybrid SLI setup must manually change modes between HybridPower and GeForce Boost, while automatically changing mode will not be available until future updates become available. Hybrid SLI currently supports only single link DVI at 1920×1200 screen resolution.^[19]
• When using SLI with AFR, the subjective framerate can often be lower than the framerate reported by benchmarking applications, and may even be poorer than the framerate of its single-GPU equivalent. This phenomenon is known as micro stuttering and also applies to CrossFire since it is inherent to multi-GPU configurations.^[20]

 

As you can see there are a lot of "if's" and "gotchas" associated with SLI support.  In nVidia's defense, it probably does make more sense for the support of multiple GPUs to reside on the application development side under DX12 as that would provide the most efficient use of multiple GPUs -- freeing nVidia to just make sure drivers are DX12 compliant.  Of course, DX12 is still pretty rare for any game/sim and it's usage does increase the development cycle (time) and costs.  So as a results, I'd dare suggest only big AA titles will go DX12 and support multiple GPUs IF they feel they need to support multiple GPUs to get the best experience from their game/sim.

 

But as we've all experienced, as nVidia progresses with new drivers they often break other games/sims and/or perform worse in some games/sims and better in others ... it's very much hit and miss (which is driven by the multitude of combinations on how graphics rendering can be worked/coded).  Conflicts surface when you need one driver for game/sim X to work, but another driver for game/sim Y to work.

 

Anyway, I hope nVidia will fix the SLI issue, but who's to say they will not break it again down the road?  My expectation was that since nVidia did create (with LM's help) an SLI profile specifically for P3D that they would ensure it's insulated/verified against and changes they make to drivers, apparently my expectations are wrong.  Since that is not the case, I'd recommend once you find a good working driver stick with it as long as you can (this might be difficult if you use other games/sims that require updated drivers).

 

Cheers, Rob.

[Cruachan 705]

Hi Rob,

 

Thanks for that very comprehensive response. Your reasoning and arguments are, as ever, appreciated and very persuasive. Like you, I am still hopeful that nVidia will continue providing support for their P3D SLI profile, all the more so as I remain determined to stick with Windows 7 for as long as is feasible. I have a few games which are sufficiently cerebral, complex and work very well under SLI. Consequently these are likely to keep me entertained for some years to come. Your advice regarding drivers is bang on and I can see that this constant need to upgrade may not be entirely justified when currently installed software neither needs nor demands it.

 

I am more than happy these days with my P3D installation and find myself growing increasingly reluctant to apply updates when there is little currently being offered of value to the end user like me. Updating for updating sake is not always the most sensible thing to do.

 

Regards,

Mike