Perfect SLI Scaling w/ rFactor 2 - Great Job ISI!

[Spinelli]

Settings and PC Info
- ISI NSX and Portugal, 12:00 AM, Rain, no opponents, pit garage
- GPU: 2x GTX 970 (SLI)
- Nvidia Driver: v353.30
- Nvidia Profile: All default except using "prefer maximum performance" and max pre-rendered frames @ 1.

NOTE: The overall framerates for these tests aren't nearly as high as could be due to the tests being performed while my GPU, RAM, and CPU were at the following slow default speeds:
- GPU @ 1315/7000 MHz core/memory (instead of 1500/7500 MHz)
- CPU @ 3.6 GHz (instead of 4.5 GHz)
- RAM @ 16-16-16-39 2T timings (instead of 11-11-11-26 1T)

TEST #1

Default Compatibility Bits - 0x02402005 (Sanctum, UAZ Racing 4x4, rFactor 2[rFactor2 Mod Mode.exe], etc.)
With the default SLI comp. bits I had some real weird results...
- Cockpit camera, both GPUs around 55% usage and poor SLI scaling and framerates
- TV cam, same thing, both GPUs around 55% usage and around 75 fps
- Chase cam (or any other cam like the cam near the wheels, side panel, etc.) and the framerates rise to 145 fps with both GPUs showing 98% usage. Wow!
- Then I go back to TV cam and, unlike the first time, the GPU usage stays at 98% and framerates in the 140s

Basically cockpit cam always SLI scaled poorly, any other cam SLI scaled great, and TV cam SLI scaled poor if the previous cam was cockpit but SLI scaled great if the previous cam was a cam that SLI scales great (e.g. chase cam)...Weird.


Using SLI Compatibility Bits: 0x02D04005
I just tried the SLI compatibility bits that I've seen others mention as of RF2 b982 called "0x02D04005 (LEGO Batman 2, LEGO Pirates of the Caribbean: The Video Game, LEGO Lord of the Rings, LEGO Star Wars III: The Clone Wars, LEGO Harry Potter: Years 1-4, LEGO Star Wars Saga, LEGO Harry Potter: Years 5-7)" and I'm happy to report that all issues are now gone and the GPU usage is at 98% for both GPUs and no matter which view is used including the cockpit view where I'm getting over 130 fps

TEST #2 Both Reflections @ "High" - everything else same as above

Default SLI Compatibility Bits
- GPU Usage = 55% (both GPUs)
- Framerate = 60 fps

Note: Always poor SLI scaling no matter the view

SLI Compatibility Bits 0x02D04005 (LEGO Batman 2, etc.)
- GPU usage = 98% (both GPUs)
- Framerate = 120 fps

Note: Wow! Each GPU's usage stays in the mid-to-high 90s % no matter what view is used and framerates are doubled. FANTASTIC!



TEST #3 - Max Graphics - except FXAA (disabled) and AA (Lvl 2)

Default Compatibility SLI Bits
- GPU Usage = 55% (both GPUs)
- Framerate = 42 fps

Note: Always poor SLI scaling no matter the view, not only that but there was major graphics corruption (solid coloured pink stuff) on the outer monitors.

SLI Compatibility Bits 0x02D04005 (LEGO Batman 2, etc.)

- GPU Usage = 98% (both GPUs)
- Framerate = 88 fps

Note: Even with all graphics settings maxed-out, SLI scaling remains pretty-much perfect (and no matter the view). The graphics corruption was also gone. FANTASTIC!



TEST #4 - Older Content
Same gfx settings as Test #3 from my OP (all graphics @ max except FXAA disabled and AA @ Lvl 2)
- Historic Eve F3
- Historic Spa
- In garage
- Night time
- Rain

Results
1x GPU = 60 fps
2x GPU (SLI) w/ default RF2 comp. bits = 52 fps
2x GPU (SLI) w/ "Lego" comp. bits = 103 fps



Conclusion: Until Nvidia sets it as default for rFactor 2, try SLI Compatibility Bits 0x02D04005 (LEGO Batman 2, etc.). The SLI experience, for me, goes from "broken" to great!

- Check out my positive Stock Car Extreme results here

 

[Sean Greenlaw]

Thanks for your efforts , looks like I should give sli another go now

 

[Spinelli]

You're welcome I was pleasantly surprised. Very impressive results.

 

[Skinny]

I'm still having terrible results on my SLI'd 970's with surround - tried allsorts including these suggestions but still struggling to get anything like playable FPS. Would you be so kind as to share your inspector profile?

One other question, just wondering how you are hooking up your monitors on your cards? My EVGA 970 FTW+ cards only have one DVI so using a DVI on each card with the top card also outputting from the HDMI port. SLI config thingy on the Nvidia site suggests this is ok but just wanted to compare . Not having any issues playing AC, pCARS etc but all Gmotor2 games are giving me major headaches

 

[Spinelli]

Weird. Maybe it's something with your Nvidia Inspector settings.

- Set you Nvidia inspector to default (don't undo settings 1-by-1, just click the default/reset button instead, don't forget to click apply).

- Go into your RF2 profile in your Nvidia control panel and do the same - click on default and then save/apply.

- In your Nvidia control panel set max pre-rendered frames to 1.

- In your Nvidia control panel set mode to maximum performance mode (rather than adaptive).

- Don't touch anything else and click apply or save or whatever it is.

- Open up Nvidia Inspector and go to the rfactor 2 profile. Make sure to change the "SLI compatibility bits" - not the "SLI compatibility bits (DX1x)" - to the 0x02D04005 LEGO profile. Don't forget to click apply/save.

Try that. I updated the OP with some more tests, it should be working for you...

 

[Skinny]

Cheers for the reply bud - think you might be right with inspector, it seemed to be changing my default Nvidia settings as well for some stupid reason. It's been a while since I did it so I've since completed a full fresh install of Windows. I'll certainly try your suggestions and post back my results

 

[Skinny]

Still no joy I'm afraid. In the NSX sat on my own on the start of LRP I'm getting a whopping 53FPS with zero AA filtering applied. Using the Lego profile it does up the stock settings up from mid 20's but still unplayable Turning off multiview does up the FPS but still not great...

So this is a fresh Windows install, all latest drivers and a fresh install of rF2 with minimal content installed. I've read posts on the ISI forums of people with 2 or 3 Titan X's SLI'd getting the same results as me. Wish to god I could figure out what the hell the issue is....sure there must be some golden setting out there....just need to find it

 

[Spinelli]

Still no joy I'm afraid. In the NSX sat on my own on the start of LRP I'm getting a whopping 53FPS with zero AA filtering applied. Using the Lego profile it does up the stock settings up from mid 20's but still unplayable Turning off multiview does up the FPS but still not great...

So this is a fresh Windows install, all latest drivers and a fresh install of rF2 with minimal content installed. I've read posts on the ISI forums of people with 2 or 3 Titan X's SLI'd getting the same results as me. Wish to god I could figure out what the hell the issue is....sure there must be some golden setting out there....just need to find it

What are your system specs and what are you getting with a single GPU? In Nvidia Inspector scroll down to the SLI section. The second setting is called "Number of GPUs to use on SLI rendering mode". Change it from the default "SLI_GPU_COUNT_AUTOSELECT" to "SLI_GPU_COUNT_ONE".

Also, with Nvidia Inspector, you should scroll down the huge list of games and select rFactor 2 so that you're working off rFactor 2's profile. Just incase you didn't.

Many people are finally getting great results now in 2D SLI (3D always scaled great) rFactor 2. You can see quite a few very good results on the official RF2 forums I linked to in the OP.

I hope we can get this working for you.

 

[Skinny]

My system specs are:

Asus Sabertooth P67 rev B3
i5 2500k (rev D2) 3.30GHz @ 4.50GHz
16GB Corsair Vengeance PC3-12800
2x EVGA GTX 970 FTW+ 4GB in SLI
Samsung 840 Evo SSD - 250GB
CoolerMaster Silent Pro Gold 1000W
3x Asus 247VN 24" monitors @ 5760x1080

I'm currently on Windows 10 but I had the exact same issues whilst on Windows 7. If I drop to a single card, the FPS drops into the low 30's. Afterburner shows both cards pushing high 90% they just can't seem to deliver good FPS. CPU usage seems to average around 50% across all 4 cores.

I appreciate by motherboard is only PCIE 2.0 and these cards are 3.0 (also running in SLI @ X8 rather than x16) but from what I've read, that shouldn't be a big factor. I can certainly play Assetto Corsa maxed out and pCARS at everything one click down from ultra.

Oh and yes, I did select the rFactor 2 (rfactor2.exe) profile in inspector to start off with.

Thanks for all your help on this

 

[billyblaze13]

first of all make sure you have sli enabled in nvcp (by default is disabled, have to change that every time i update driver)...second the default settings have the last line of the sli settings as force sfr you have to change this to force afr_2.....also the default settings have override application aa this will only work if the setting under antialiasing sli aa is set to disabled....i get best performance using ingame aa with antialiasing sli aa set to enabled

 

[Skinny]

Hi, thanks for the suggestions, tried them and still poor FPS. I tried turning all graphics options to low or off and frames went up to around 150ish. Just not understanding why my system seems to hate this game - at low I'm only just beating the FPS Spinelli was getting with the graphics set as per his screenshot. I could understand if it was like this for all games but as I posted before, AC & pCARS both run great, Battlefield 4 runs fine on ultra settings - all of which are massively superior graphically. I used to be running rF2 fine on my old 670's SLI'd on a single HDTV (all other components the same) but this new setup just seems to kill it .

 

[billyblaze13]

weird....i have gtx 660 sli that i run through a sony 55" 4K HDTV and i can get locked 120 fps (alone on track) using
DSR 1.5x and level 5 ingame aa with all settings maxed except reflections off and the game looks great...i have also played in 4k and was able to get up to 55 fps with some settings turned to medium (looks amazing in 4k ).....for me rf2 is a different game above 100fps i try to get settings that allow locked 120fps and it really gets good.....anything below 100 feels laggy to me...maybe because i am playing on a tv

 

[Skinny]

Yeah seems to be rather system specific this game - read a good few posts saying how lovely SLI has been over the past couple of builds and plenty others having the same issues as me. SLI on a single screen seems to be ok but SLI on triples especially with multiview enabled seems to be a killer - at least for me anyway.

 

[Skinny]

Ok it seems the multiview is the killer setting for me. I best I got on the start line with 10 AI's with multiview and half decent graphics settings was low 50's FPS - with multivew turned off on the same settings I'm getting 115FPS.

 

[Spinelli]

Paul, your motherboard is only PCI-E 2.0 and with 16 lanes. Then with SLI you cut those lanes in half at 8x each, but, 8x lanes in PCI-E 2.0 is equivalent to only 4x lanes with PCI-E 3.0. So you're basically running both of your GPUs at 4x instead of 16x. It gets worse though. Most games only suffer around 3-5 % when going from PCI-E 3.0 16x down to 8x, but rFactor 2 for some reason is an exception and there have been many tests about this in the official ISI rFactor 2 forum and people, including me, have seen framerate increases of 10% to a whopping 40% just by going from PCI-E 3.0 8x to 16x, and you're essentially running 4x in SLI or 8x in single GPU mode.

first of all make sure you have sli enabled in nvcp (by default is disabled, have to change that every time i update driver)...second the default settings have the last line of the sli settings as force sfr you have to change this to force afr_2.....also the default settings have override application aa this will only work if the setting under antialiasing sli aa is set to disabled....i get best performance using ingame aa with antialiasing sli aa set to enabled

View attachment 99600

All that's unnecessary. SLI is not disabled by default, it's at auto like with pretty much any game. It doesn't have to be enabled anywhere. And the AA thing is incorrect as well. AA by default is application controlled not override application. You don't need to adjust or enable any special SLI AA settings, that's only if you want one of your graphics cards to only process AA rather than the game, and then the other GPU takes care of the game and some AA too.

 

[Skinny]

What motherboard are you running Spinelli? Looking to do an upgrade later in the year to the new i7 series CPU so will be needing a new mobo and RAM too. Not seen much that offers dual x16 lanes for SLI last time I checked.

 

[billyblaze13]

hey Spinelli I know you're the graphics guru and i'm not trying to argue with you just trying to help the guy out i've been using rf2 with sli for the past year and a half and that's how it is on my system....

if i don't enable sli on this screen it simply does not work....every time i update my driver it changes to disable sli and i have to change it back it does not work "automatically"....
also when in inspector when i click restore nvidia defaults on rf2 profile this is the result

bottom line if i do not change it to the settings i told Paul it doesn't work properly....again like i said on my system

 

[Gijs van Elderen]

i'm not trying to argue with you

And nobody will.

You are using a single screen with SLI.
Spinelli is using triple screens with SLI

2 completly different things.

 

[Skinny]

Yip when I was running SLI'd 670's on a single screen, SLI would disable after every new driver too

Thanks for all the suggestions too, it seems I'm gonna have to sit and fiddle with the graphics options to find a happy balance until my upgrade - since rF2 seems to hate my setup lol

 

[billyblaze13]

And nobody will.

You are using a single screen with SLI.
Spinelli is using triple screens with SLI

2 completly different things.

okay thanks