rFactor 2 with SLI and triple screens - tips for good performance?

[Billy Pilgrim]

I'm getting a three-screen setup and will be using two GTX 780 GPUs.

I've heard that rF2 doesn't perform well with SLI and triple screens. But I'm really hoping to play rFactor2!

Is there some way to make it work well in SLI? With high settings and good fps across three screens?

I did find this btw:
http://isiforums.net/f/showthread.p...-w-Multiview-otherwise-OK-w-triples-or-single
which seems to be a possible solution. Is that the best there is?

 

[Richard Eriksson]

The rendering pipeline has trouble with SLI setups still... And for triple screens, it seems it's a bit hit and miss if you get a correct picture or not.

 

[martcerv]

I cant get RF2 2 work with SLI on my 2x Titans and have tried nearly everything. SLI single car on track 2560x1440 max settings 34fps single card 90+ fps but struggles with other cars on track much worse then it should.

RF1, GSC2013 and AC all work great in SLI not sure what it is with the RF2 engine but looks like we need some new drivers to get it going. I kind of lost interest in RF2 but these new Karts are really good so would hope to get SLI working at some point because getting worse graphics and much worse performance then AC really makes me struggle to fire up RF2 which I really liked in the past.

 

[martcerv]

I did find a setting that kind of works with NV inspector forcing NV bits 0x00500005 (Windows System Assessment Tool) this gives much better performance in SLI but it has some texture flickering. Not as bad as I remember in earlier build but still a little annoying. I think turning off HDR may solve that flicker issue.

This has got me single kart on track 107fps in one card and 187fps in SLI pretty much the same from cockpit view and also tv cam view.

Back of 29 kart grid FPS single card 44.8fps and SLI 62fps so unlike the default RF2 profile that actually makes it worse this tweak gets SLI working.

As I am a single screen user I cant say how that will translate to triples but at least I found a way to get SLI to work so I am happy about that. Here are some screens showing my SLI on and OFF tests the images arent labeled but if you see GPU 2 with much lower load and lower clocks this indicates SLI is off and just set to single card mode.

https://www.mediafire.com/?c08s9h5tt9rj780

 

[Chris Partridge]

Stick to the default profile in the driver. BTW, I get 35% higher FPS with my single 780Ti 3GB v my old 2 x GTX 680 set up.

 

[Blkout]

Stick to the default profile in the driver. BTW, I get 35% higher FPS with my single 780Ti 3GB v my old 2 x GTX 680 set up.

If you read carefully above you would realize this is because rFactor 2 has a problem with SLI in that you actually LOSE framerates when you enable the default Nvidia SLI profile. Its really no surprise that your single 780ti is 35% faster if you were using your SLI 680's with the default Nvidia SLI profile since that basically forces the game to run worse than even using a single 680. If the SLI profile were working properly like most games, your two 680's would be faster than a single 780ti.

 

[Chris Partridge]

If you read carefully above you would realize this is because rFactor 2 has a problem with SLI in that you actually LOSE framerates when you enable the default Nvidia SLI profile. Its really no surprise that your single 780ti is 35% faster if you were using your SLI 680's with the default Nvidia SLI profile since that basically forces the game to run worse than even using a single 680. If the SLI profile were working properly like most games, your two 680's would be faster than a single 780ti.

Except I get higher FPS in AC and pCARS too on my 780Ti. I initially thought the same as you several months back.

 

[Blkout]

Except I get higher FPS in AC and pCARS too on my 780Ti. I initially thought the same as you several months back.

It should be very close honestly, two GTX 680's are slightly faster than a GTX 690 and the GTX 780ti is sometimes faster than a 690, but not all of the time, its a damn toss-up assuming SLI is scaling properly which in the case of rFactor 2, it was not at all. Don't get me wrong, I'm not bashing you for going to a single 780ti from two 680's in SLI since the speed difference is fairly close but you gain more consistency with a single card when SLI isn't working properly. For me, a single 780 wasn't enough so I went with two 780's anyway.

If you thought the same as me months ago in regards to rFactor 2, then you were correct at that time. The problem with rFactor 2 in SLI is not only does it not scale, it negatively scales meaning instead of getting 60fps with a single card, it does 30fps in SLI which is worse than a single card. Very few games negatively scale in SLI, and in those cases, you're better off disabling SLI for that particular game which is what I do in rFactor 2.

 

[Chris Partridge]

But then why am I getting 30% better FPS in AC and pCars. And I use the appropriate files in the latter and the former had them anyway.

 

[Blkout]

But then why am I getting 30% better FPS in AC and pCars. And I use the appropriate files in the latter and the former had them anyway.

I can't answer that question Chris, I didn't setup your PC when you had two 680's in SLI and since I can't see how its setup now since you don't have that setup then its pointless to debate. The facts are though, looking at just about any benchmark you want, two 680's in SLI are slightly faster than a single 690, and a single 780ti is sometimes slightly faster than a 690 but not all of the time. If SLI was working properly, I would expect the two 680's to run every bit as fast as a single 780ti if not slightly faster most of the time.

You can go through this 780ti review and see game by game how a 780ti compares to a 690 and keep in mind as I stated that two 680's are faster than a 690 100% of the time since the 680's have a higher core clock speed. A 690 is nothing more than two 680 on a single card with reduced core clock speed in order to stay under power TDP requirements.

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_780_Ti/7.html

 

[Billy Pilgrim]

What do you reckon:
When would you expect rFactor 2 to be optimised for SLI/CF? How long does that sort of thing take in the world of pc race sims?

Would you expect it to be optimised in, say, six months, 12, 18, never?

 

[Blkout]

What do you reckon:
When would you expect rFactor 2 to be optimised for SLI/CF? How long does that sort of thing take in the world of pc race sims?

Would you expect it to be optimised in, say, six months, 12, 18, never?

Its pretty dissapointing to say the least. I don't know if the blame falls on Nvidia or ISI, but what doesn't make sense to me is that there is an Nvidia SLI profile for rFactor 2, you can see it in the Nvidia control panel but yet it performs worse than a single card when you use it so its a little baffling to me.

All of the other PC racing games and sims that I own have proper SLI support.

 

[Chris Partridge]

I can't answer that question Chris, I didn't setup your PC when you had two 680's in SLI and since I can't see how its setup now since you don't have that setup then its pointless to debate. The facts are though, looking at just about any benchmark you want, two 680's in SLI are slightly faster than a single 690, and a single 780ti is sometimes slightly faster than a 690 but not all of the time. If SLI was working properly, I would expect the two 680's to run every bit as fast as a single 780ti if not slightly faster most of the time.

You can go through this 780ti review and see game by game how a 780ti compares to a 690 and keep in mind as I stated that two 680's are faster than a 690 100% of the time since the 680's have a higher core clock speed. A 690 is nothing more than two 680 on a single card with reduced core clock speed in order to stay under power TDP requirements.

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_780_Ti/7.html

Yes - I was aware of the differences from the 680 Sli to 690... Perhaps my 680s were inadvertently underclocked? Still, think this is a better solution at hi res because of 3GB and single card consuming less juice from the PSU. However, there is no difference to any perceived stuttering - there was none before in SLI for me and none now on single card solution.

 

[Blkout]

Yes - I was aware of the differences from the 680 Sli to 690... Perhaps my 680s were inadvertently underclocked? Still, think this is a better solution at hi res because of 3GB and single card consuming less juice from the PSU. However, there is no difference to any perceived stuttering - there was none before in SLI for me and none now on single card solution.

Again, I'm not disputing your change, if you can get a single card to perform almost as well as two cards, then that's usually the safer bet. I was only speaking about how rFactor2 has a major issue in SLI and that's why it performs so poorly. All other games I own, racing or any other, perform well in SLI as they should.

 

[Billy Pilgrim]

...All of the other PC racing games and sims that I own have proper SLI support.

May I ask: What other pc racing games do you own (that are good in sli)?

 

[martcerv]

But then why am I getting 30% better FPS in AC and pCars. And I use the appropriate files in the latter and the former had them anyway.

For me AC always worked better then RF2 on single cards and in SLI its really not even a contest as RF2 is so bad at SLI, since the latest beta drivers AC fly's for me. I can get SLI working in RF2 but it then has some flicker issues which can be mostly solved I found by capping FPS at a multiple of the refresh rate. As long as the frame rate stays there it has no flicker but go off it and it is very annoying. Then you need to make so many tweaks to avoid all the issues of the engine it really is quite badly coded compared to the AC pre release.

A single car will generally always outdo a SLI setup with similar physical specs as SLI never scales 100% where it will double frames. RF2 sadly is just very badly optimised graphically and the gfx engine realistically needs a complete overhaul I think maybe when Dx12 comes out they should consider doing a full rebuild as it really needs it.

The default SLI profile I really wonder why that was even added by Nvidia as it clearly doesnt work at all. The older RF1 engine and all other sims based off that work great in SLI and really dont look too much worse then RF2 graphically and apart from HDR which is broken anyway everything else graphically could be done in the RF1 gfx engine.

I cant think of any other racing game or sim that doesnt work in SLI, goat sim doesnt lol but still single card looks way better then RF2 and also higher frames. Beam NG works well RF1, GSC2013, codies arcade titles, NFS crap all work its really just RF2 that doesnt. Oh Next car game doesnt work in SLI but that is barely alpha and I have no idea why I bought that rubbish. I guess it will get better and may be fun in some way down the track but for me AC is my choice sim and for a bit of fun beamNG is way better then NCG.

I dont have Pcars but that clearly runs great in SLI and ISI really need to pull their fingers out and do something about the gfx engine which is pretty much just a poorly patched sports car GT engine, which I think was their first sim and really doesnt look much different how many years later.

 

[Chris Partridge]

I disagree - rF2 looks great for me and I get better FPS than in pCars. Sure pCara might have some nive effects but they don't bother me really. SLI in rF2 could be better optimised.

 

[Blkout]

May I ask: What other pc racing games do you own (that are good in sli)?

iRacing, Assetto Corsa, Game Stock Car Extreme, GTR 2, Race07.

 

[martcerv]

SLI in rF2 could be better optimised.

Seeing it cuts your frame rate in half using the default profile id say your correct about that. They should market it that way go buy a second GFX card so you can get half the frame rate of just one card

 

[pingpong]

Hello

In the latest build 660, when using Nvidia inspector, the Rfactor2 SLI profile does not give any advantage, neither does using the Windows System Assessment Tool profile anymore.

I tinkered around and got all my SLI advantage back by using the Crysis 2 profile. Simply look at the profile for Crysis 2(another DX-9 game) note the SLI profile number and set the same in the rfactor2.exe profile.

Works great for me, all my framerates came back.