NVIDIA compatibility bits master thread and IQ guide

you can't make sli profiles for dx12 and the game is so crazy with the deferred rendering i doubt you will get dx11 working.

 

Trying to understand how to use this compatibility list after reading initial post. Let's assume for example I have Assetto Corsa game. According to Compatibility list I can:
1. Enhance ingame MSAA with SGSSAA
2. 0x000040F5 (Also set "0x00A0694B" to "0x00000000")

I wonder how to apply 1 and 2 in NV Inspector to the profile of this game. There is so much options in NV Inspector in Antialiasing but I can't find any with the name SGSSAA in it. Any hints for novice user?

 

Well, here is an example of enhancing ingame 4xMSAA with 4xSGSSAA in Just Cause 2.
Using an older version of Inspector though.



You just enable the desired level of ingame MSAA, and then use "Transparency Supersampling" to set SGSSAA.
In regards to the undefined SLI bits, I only included the "code names" in the spreadsheet due to NDA restrictions.
But the SLI function you refer to is simply called "SLI Broadcast (DX1x)" in newer versions of NVIDIA Inspector.
Here is an example of it "in use":

https://www.forum-3dcenter.org/vbulletin/showpost.php?p=11918860&postcount=3205

Hope that clears up any confusion.

 

Added and/or updated a few more SLI profiles recently.
However PC gaming really isn't my main "occupation" at the moment

 

Hi @GuruKnight ! I've been trying to do you proud by building an SLI profile for a game I've been playing as a playtester. I've got most everything working...
At game load/the start of each map some assets will be flickering, I need to go into settings and flip the 'effects' setting to something else then back, and the flickering stops and SLI works great with about 30% scaling until the next map, where I load in and repeat the process.

Except when we switch to one specific map, the workaround appears to work initially, but eventually SLI freaks out, and the workaround of flipping the effects setting no longer works.

I have a clip on twitch here that shows the problem: https://clips.twitch.tv/CautiousSmilingEggplantLitFam

The SLI profile is as follows:

Code:

Set SLI Broadcast (DX1x) to 0x00000001 DYNAMIC_BROADCAST_RENDER_TO_TEXTURE
Set SLI compatibility bits (DX10 + DX11) to 0x080002F5
Set SLI Specific Hacks (DX1x) to 0x00820401 (Have also tried 0x00010020 and 0x000600220, same problem)
Set NVIDIA predefined number of GPUs to use on SLI rendering mode on DirectX 10 to 0x00000002 SLI_PREDEFINED_GPU_COUNT_DX10_TWO
Set NVIDIA predefined SLI mode on DirectX 10 to 0x00000002 SLI_PREDEFINED_MODE_DX10_FORCE_AFR

These are the variables being changed in UE when the effects setting is toggled:

Code:

[EffectsQuality@3]
r.TranslucencyLightingVolumeDim=64
r.RefractionQuality=2
r.SSR.Quality=3
r.SceneColorFormat=4
r.DetailMode=2
r.TranslucencyVolumeBlur=1
r.MaterialQualityLevel=1 ; High quality
r.SSS.Scale=1
r.SSS.SampleSet=2
r.SSS.Quality=1
r.SSS.HalfRes=1
r.EmitterSpawnRateScale=1.0
r.ParticleLightQuality=2

If you've got any idea of something I can change in the profile to prevent the issue, that'd be ideal. But if you happen to know what exactly is causing the problem on the dev side, I can let them know.

 

I'm not exactly sure to be honest, as SLI testing in UE4 can be very tricky even for experienced users.
There are no "general" SLI solutions when it comes to this engine, and it is very game specific.
But it sounds like something I ran into when testing "What Remains of Edith Finch" quite a long time ago:

https://www.forum-3dcenter.org/vbulletin/showpost.php?p=11918860&postcount=3205

In this case it was related to the screen space reflections, and I solved it by creating a Engine.ini file and putting these commands into it:

[/Script/Engine.RendererSettings]
r.SceneColorFormat=3
r.SSR.Quality=0

I suggest trying just 0x080002F1 combined with setting the SLI broadcast flag to 0x00000001.
There should be no need to enable any additional SLI hacks, and this might cause further problems if these driver functions are not needed.

 

Was afraid you'd say something like that! Thanks so much for the response.

Unfortunately this combination of bits and broadcast flickers on all levels and even the effects workaround I described doesn't work.

I did also put the settings for r.SSR.Quality=0 and r.SceneColorFormat=3 into the game's Engine.ini and it doesn't seem to pick them up. I'd tried doing similar things by creating a scalability.ini to change the settings, but those also don't seem to be working for me. I'm following up with the devs on this bit, but according to the reference they gave me, these values should be set if I set the Effects setting to Low.

I will say, the SLI hacks are what makes the 0x080002F5 profile work at all... Without them it's flickering all the time. I did try them with your suggested compatability bits and no dice though, it didn't work as well as what I have already unfortunately.

Is there a reference I can read to learn what each value on the compatability bits and hacks does?

 

Well such information is NDA restricted unfortunately, so I can't really speak about it in detail.

But as a last effort you could try 0x080020F1 combined with setting the SLI hacks function to 0x00010000 or 0x00010100.
Or maybe 0x080022F1 combined with a broadcast value of 0x00000001 and the same SLI hack value.
Alternatively try 0x080000F1 or 0x000000F1 combined with a SLI hack value of 0x00010020 or 0x00010120 and the broadcast flag disabled.

However there are so many combinations, that I can't really provide all the possibilities here.

 

Thanks for the follow up! I'll probably not be able to test until this weekend. I'll circle back here and let you know the results.

 

Sadly, no joy with any combination. RIP. The devs are looking at DLSS2.0 at least!

 

Brotha I didnt undersrand 1 word comin out yo mouth, all i heard was bleep bleep mothafakin bleep.

 

beep boop

 

hey guys do you think its possible to toggle gsync on/off with a command line using nvinspector ? I have a bugged samsung 4k monitor that I need to power cycle or toggle gsync on / off after sleep in order to eliminate some synchronization issues.

 

Well, it makes no sense to just show up in my thread to say such things.
My message was targeted directly at Zoson to help troubleshoot SLI in a specific UE4 game.
From what I can see, you are not even an SLI user?
So of course you would know little or nothing about detailed SLI testing and such things.

But to answer in more detail, I was referring to the more advanced SLI functions of the driver.
A good example of all of these functions in use would be an SLI profile I found a while ago for another UE4 game, namely Conan Exiles.



My full post from the 3DCenter SLI thread can be found here:
https://www.forum-3dcenter.org/vbulletin/showpost.php?p=12339576&postcount=3817

But naturally all such information is already included in the master list spreadsheet and has been so for a very long time.
Hope that clears things up

 

RIP SLI:
https://nvidia.custhelp.com/app/answers/detail/a_id/5082

It seems this work will be more important than ever.

 

You understand that the hacks won't work on the 3090, right?

 

I'm not sure to be honest, but that is not what the article is directly saying.
It only states NVIDIA won't be making "official" driver SLI profiles for 3090.

However as I already said, I have very limited time at the moment to do further testing.
Right now only the current content in the spreadsheet will be maintained from my end.

But the future for SLI clearly lies with DX12 and Vulkan MGPU implementations ingame.
And NVIDIA choosing to focus mostly on this is not necessarily a bad thing in the long run.

 

I don't think that's true. They're going to keep existing SLI profile support for games that have it already. Which means all the bits/hacks will still be in the driver. NVIDIA just won't be making profiles themselves.

The way I'm reading the article is that NVIDIA isn't going to even help devs do dx12/vulkan multi gpu. They're just putting all the responsibility on the game devs. Sadly, there's basically be no interest at all in multi gpu in DX12/Vulkan outside of proof of concept stuff like ashes of the singularity. Even games that historically relied on SLI like the racing simulators arn't supporting it in their new releases.

 

we'll find out soon enough.

 

I too am confused about this .. why make it NVLink capable in hardware when you are exclusively targeting explicit DX12 mGPU? I wont have an upgrade path if nvidia sticks to its guns