DCS 2.5 with SLI\CROSSFIRE

So... I was wondering if there was a possibility to make SLI\CROSSFIRE work with DCS 2.5?

I know that thus niche has been dying out for a long time now, but I really love the idea of combining graphical firepower in a new setup I want to build.

Any thoughts?

Read Rig info below. Mine screams....

Yes but does DCS take propper advantage of it? Does it really boost your fps?

Just my opinion and experience, but having tried sli with 6 different 1080 and 1080ti combos, I felt the advantage was..minimal, at best, and non existent at worst. I wish it wasn’t the case, believe me.

Yes but does DCS take propper advantage of it? Does it really boost your fps?

That’s the question isn’t it, and IMO, no, it doesn’t, at least not very much. Any performance gained in DCS through SLI is mostly a placebo effect, again IMO.

SLI works great in 2.5.0 Release. Up to 100% performance improvement (double framerates) if your GPU is the bottleneck. But, you need to do a little tweaking to make it work properly (the default Nvidia profile does NOT activate the SLI performance bits in DCS - only one card is used. Which is why most people think there is no improvement with SLI). So, I wrote a guide to make it work properly to utilize all the cards in a SLI rig, here => https://forums.eagle.ru/showpost.php?p=3410823&postcount=65

However, 2.5.x OB broke it - now, there is bad cloud flicker (I suspect clouds are not rendered every frame) and I haven't found a fix yet. I wish DCS DEV's would roll back to the cloud rendering used in 2.5.0 (or give us an option to set every frame, like the TGP displays)

Nice - greatly appreciate the technical info and the work done on measurements.

I am running standard NVidia Profile and I think SLI has kicked in. VR stability and overall usability came only after SLI. I created the machine for Prepar3D to run at over 70 FPS, and it does just into 100 fps. Bonus that it has made DCS a playable simulator for me in VR mode.

Out of VR mode I'm getting 90-134 FPS per the counter in DCS. Monitor is 2560x1440 at 165hz.

This is flying the F-18C over one of the cities in the Persian Gulf. Low level flight is 90ish fps and 8kft 120+ fps

Bit slower in VR mode, frankly not a lot.

I'll have to see if there's an indicator I can run to check for SLI mode. Or this is just fast CPU/GPU.

My lame little video. If you squint in the upper left is the FPS counter. I ran the Nvidia overlay (doesn't record) and it's counter matched the in-game.

I used the Caucasus usually slower and harder on the FPS. No stutter when playing, the playback slight stutter is in the recording.

https://youtu.be/pYqOOYmJpY8

Hrrm, maybe I've given up too soon on SLI, I'll try out your link there Cowboy and see if it works in our 1080ti SLI system.

As far as I know and have read here, SLI doesn't work in VR, nor in any other game. Is that outdated info too?

For all I know, the Oculus VR API doesn't yet support any multi-GPU.

I may add a card if mGPU in Vulkan works, C E R T I F I E D.

With SLI....hell no, no more.

I can't say at all that I get SLI in VR. I'm not so technical as to know if it is or isn't.

Sounds like it's pretty clear that it isn't, thank you, techies, for sharing..ugh.

With no SLI in non-VR mode, getting 140-150 fps max in full screen is quick. **Sounds like I'm better off with a 1080 Ti card though...

I set Fraps, Bandicam and internal FPS monitors running. All report the same.

• 45 fps max in VR at 1.8 PD. All other settings per recommended for VR.
  
  Never goes higher, only lower.

  
  

• 120-150 fps max in non-VR mode.
  
• Reported by Fraps Benchmark, Fraps FPS, Bandicam, DCS Internal.
  
• 2560x1440 on ASUS ROG PG279Q @ 165hz G-Sync On

  
  

Install MSI Afterburner software suite to monitor your GPU usage(s).

You then clearly see if YES or NO, and to what extend.

* configure the OSD to show what you need, default doesnt.

Install MSI Afterburner software suite to monitor your GPU usage(s).

 

 

You then clearly see if YES or NO, and to what extend.

 

 

* configure the OSD to show what you need, default doesnt.

Roger - will do that today.

Thanks!

Have you been able to check it out, Thud?

Overkill for this game .. one 1080ti is more than enough.

Have you been able to check it out, Thud?

Yes - today I finalized my rig.

The 1080 Ti card is definitely faster than the SLI 1070 cards.

I did leave one 1070 card in place, Nvidia seems to be using that for all the Physics.

In addition, I completed the overclocking of my PC to 5.0ghz and XPS mode memory.

I'm getting 170-190fps on-screen.

90 fps with occasional drops no lower than 70 in VR mode on Oculus.

1080Ti wins!

Love to hear if anyone is running a TitanX card lol.

Is there a way to see if the VR framerate is more due to the 2d GPU or because of the overclocking? I get around 36 fps. What is superclocking the GPU? And especially do you see an occasional tear/stutter/spike in DCS with VR?

Is there a way to see if the VR framerate is more due to the 2d GPU or because of the overclocking? I get around 36 fps. What is superclocking the GPU? And especially do you see an occasional tear/stutter/spike in DCS with VR?

AGAIN, VR does N O T use 2 GPU's at all. The API from Oculus/Facebook only uses ONE GPU.

https://www.vrheads.com/can-i-use-both-graphics-cards-vr

But DCS doesn't use LiquidVR etc. No proprietary technology is in the works.

Ok, ok.... Yes, we know it doesn't use both. That's what ED says, ok....

Now, let Thud answer the question about why his framerate is so much better than mine. At some point these questions are useful to some of us. There's no reason to keep beating the 'it doesn't use SLI' horse anymore....

Ok, ok.... Yes, we know it doesn't use both. That's what ED says, ok....

 

Now, let Thud answer the question about why his framerate is so much better than mine. At some point these questions are useful to some of us. There's no reason to keep beating the 'it doesn't use SLI' horse anymore....

Thud as far as I can se ehas not yet stated his LOD and PD. Without those, any fps value said is meaningless. You need to know his exact settings so you can compare apples to apples and not be fooled by a foul comparison out of not-knowing-how-to.

Thudster needs to tell us his setting so we can quantify his fps statements.

Also, I can get twice the fps in some airframes compared to the most taxing ones. Knowing what he flew while he did that is just as important as LOD and PD.

A fps statement alone is useless. No offense.

No offense at all! I appreciate the insight! Just trying to learn, after all. Makes perfect sense, hadn't thought of that. I was looking purely at the hardware, forgot about settings.Thanks!

You'd really have to match it with the same instant machine. You should also OC to 5GHz, make sure background processes match etc. I don't now how the 1070 is connected (vis a vis monitor). Also, you have to compare the 1080Ti in control panel to see if Performance mode is chosen.

There are like 5 -10 things to compare and rule out before jumping to "multiple cards" help. I'm not saying it doesn't, but you have to rule out the usual suspects first. When you hear hooves beating, you have to think horses and not zebras.

And aren't those wings supposed to be gold? And if you don't mind my asking (not that familiar with Marine insignia), what is that on top of the the wings?

Now that was a REAL LOL! Horses and Zebras !! Lmao

In real life I was Marine Force Recon for most of my 20 year career. The top insignia is the Combat Diver Insignia. We call it the Bubble. That's the old style. The new insignia is gold and is a different style. The wings are Navy and Marine Corps Jump Wings.

I realize to benchmark properly and compare would take exact specs. I think knowing how he thinks it works is fine too. His specs are like mine and I'm considering overclocking.

Now that was a REAL LOL! Horses and Zebras !! Lmao

 

In real life I was Marine Force Recon for most of my 20 year career. The top insignia is the Combat Diver Insignia. We call it the Bubble. That's the old style. The new insignia is gold and is a different style. The wings are Navy and Marine Corps Jump Wings.

 

I realize to benchmark properly and compare would take exact specs. I think knowing how he thinks it works is fine too. His specs are like mine and I'm considering overclocking.

Ah, gotcha. When I went to jump school, all the Marines were looking forward to making five more jumps to get the marine/navy wings. Didn't know about the diver one. I'm sure it's every bit as difficult as other branches diver course.

Back on topic, OC is not that difficult anymore. There are plenty of guides that are MB/BIOS specific. But there are plenty of knowledgeable folks around here so don't hesitate to ask!