DX11/DX9 low fps/stuttering with SLI setup and multiview

Hi all,

After lurking around for a long while and +800h AC it was time to expand my sim titles, looking at RRE and RF2, tried both and RF2 seems to be better for me with some very nice features and rich content.

Unfortunately after almost 20h testing I can't get the gfx setup to work in a good way.

My specification is i7-7700k, 2x1070 SLI (asus strix) and 3x27" with 7680x1440 gsync, everything OC 10%. As reference, AC with everything almost at max running smooth 90-120fps, all tracks, during races.

One reason why rf2 is a better choice over RRE is correct multiview and upcoming dx11.

In my test I have been using high settings (also tried max and it had little impact)
With DX11, no post effect, AA set to level 3 and anisotropic filtering x4
Reflection low, shadows optimal
Sync set to none, gpu, video, do only affect a few fps
Fullscreen
In all test, cpu load seems to be around 75% (estimated in game value)

Track San Paulo, 10 car race with the Radical (even if result is similar on other track/cars combos)

So I have tried:
DX11+DX9 standard setting, both around 25fps
low gpu usage, 55%

SLI bits
DX11, 0x08040F5, 0x08000F5
25-60fps (with or without other cars)
with cars, alot micro stuttering
track only, some stuttering
"slow motion" feeling when around other cars
gpu usage, both 99%
With high post effects but no AA, 5fps drop

DX9,
0x02D04005, 50-120fps
0x02D02005, 60-110fps
gpu load 90-95%

The last bits even with a bit lower fps, works best but still stuttering and drop in fps when around other cars, even one.

If I try above borderless, fps drops 25-30fps


Running out of ideas to test (and I really like the sim, some very nice physix and ffb right out of the box) I decided to turn of the multiview.

DX9 (DX11 not tested yet)
90-120fps (limited in json to 120)
no stuttering, all smooth gameplay....


That is really great, in the radical it is almost ok but in almost every other car the side monitor car stretch and giant sidemirror effect is not so good (that is the same as RRE triple support)


So if anyone have any suggestion or idea what to test or setup to make it work better with multiview that is very much welcomed

 

https://forum.studio-397.com/index.php?threads/dx11-beta-sli-compatibility-bits.55306/

 

Thank you for your answer Ari,
I have seen your post in the end of the thread before (the nvidia inspector was new to me) and I have edit the json as you mention, I will go over it again and see if there is any combination I have not tried or setting missed.

Also you mention HDR, that is not an option in the latest release of rf2 (I can't find it anyway)?

I see you also seems to run nvidia SLI and triples and getting 120fps, are you using multiview as well in that setup?

 

HDR is not option in DX11 settings.
Yes I am getting 120 fps with triples multiview on with DX9.
I can see that latest DX11 Build ID : 1941092 has support for mulit-gpus and multi-monitor selection, available via drop downs in Laucher config but I haven't tested if latest build is working with SLI or not.

 

Ok, thats great but so far no improvement here, std SLI bits with dx11 and race start 10 cars, 16 fps, so dx11 and SLI is not working correct.
I can with SLI bits get better fps but with stuttering as before.

With dx9 it actually seems to work even worse, I have notice that before the update without multiview, I did get +120fps and smooth gameplay but now the micro stuttering is still noticeable, and non multiview is actually not an option on triples for me at least.

Regarding HDR, I was thinking dx9 but that is not visible as an option for me as I have seen in some pictures.

Anyway I continue testing but right now it is not playable, but my hw should be more than good enough.

 

I think by multi gpu support in latest build notes it meant that you can now select which GPU to use in the config of the game. Probably nothing much new to SLI.

 

you probably right on that one, it actually seems to work better (or I have dialed my settings better)

it's getting closer on dx9, with SLI bits 0x02F04003 (or 5) and video sync (gsync monitors should work better without?)
i'm getting 60-120fps depending on how many cars that are close around with only occasionally stuttering of ai cars.
(high/full setting, shadows/reflection medium/low). With the LEGO bits the stuttering seems worse and maybe 10-15fps less.

I'll give dx11 another try and see if any improvement possible

 

after a day of testing I will correct myself, after testing dx11 (still not there yet) and went back to dx9, the stuttering was obvious even if the fps was +100. With sync to gpu it was without stuttering but fps drop to 50-80fps region and gpu load 2x55%

so I again tried the 0x02D04004, max pre-rendered frames 1 and sync none, 2x98-99% load and fps 50-100 range. gpu sync on this sli bits actually makes it worse ("slow motion"/micro stuttering at gpu load 95%)

with these setting dx9 both have the looks and is running ok. It actually a bit hard to say which one is better, but both do make it possible to play the sim.

will try dx11 a few more test, even without post process, it is an improvement visually, otherwise I stick to dx9 for now.
(all dx11 test have been with none post process)

 

So, with 44h according to steam and close to 400 starts of the game i'm still not found any good setup that works with SLI.

with above, yes, in hot lap it works ok but in race with ai, the stuttering is heavy and not acceptable.
going back to previous settings, stuttering is less but it still there even with no cars around.

with dx11 it is similar, with both I can get about the same fps (with no post effect) but the issue is the same as above.
Is really over more half the drop in fps normal when race 10 cars (from top 120 to around 40)??

yes, this sim more accurate than AC and RRE, but that should not affect visual performance when doing a race,
at day, during similar visual condition. If I compare to AC, with AI the drop is in the range 15fps, from 100fps.
My CPU is not even close to it's maximum levels.

So please, any suggestion how to improve performance (unless setting everything set to low) are very much welcome.

 

So to sum it up if anyone have similar problems with SLI, these are my final settings:

SLI bits



Video settings



GFX settings




On track, with dx9 or dx11 I get about 75 to 120fps.
But with AI during the start sometimes fps drops to 40-45.
I can get higher values, but then micro stutters appears, even without AI and 120 fps.
GPU load 98-99%

So I'll try going to try a online league race on Sunday and see if it works ok.

 

And as an side note, when video setting is opened in the launcher, 2nd time and onwards, the version differ



But I think I saw something about dx11 that version number is work in progress.

And as side note 2, in dx9, video memory is reported as 4gb but it is actually 8gb (x2 with SLI?)

 

So a little update, the mem thing above seems to be "normal"

Regarding the gfx, still had some stuttering, almost Ok but still. So I decided to test some fixed settings ending up with these:



Visually it made nothing I could see (but it sure is in some way) but all stuttering was gone, great.
So I tried a night race and the fps drop to around 75 max. Then decided to go back to dx9 again.

When I started rf2, all screens black and computer rebooted, tried it twice. Maybe some setting above was the reason?
So I went back to dx11 again (clearing cbash and shaders), but got an JSON error when starting from the launcher.

So I saved my player and controller files and deleted everything in UserData folder, and let Steam check the game.

Now rf2 started again, did again a 15 car night race, after the start the fps was steady 90-120fps even in traffic!
Did a day practice and with no cars around 120fps (locked) and GPU load down to 65% (and up to 99% if needed).
(non ISI content, dx11, no post effect)

SLI do seem a bit tricky, almost 60h to go from 15 to 120fps (ok, I actually done a couple of laps as well
Not sure what made this happen, setting above or some corrupted setting in the UserData folder but now I'm not touching it

 

so I update this again

I was hoping I found a way to make it work... When it start as above, with my setup, +90fps in garage it works ok.

the problem is that next time I start the game i'm back to 55-60fps in the garage and major stuttering, now I have tried everything,
delete the user dat folder, the log folder, writing settings, rebooting, change the profile etc etc and so on.

sometimes it actually starts in a way it is possible to play the sim, like 1 of 20 tries, when you think you found out why,
it doesn't matter next time you start, even if you do the same (delete folder, write over cfg files, validate, reboot etc).
the low fps and stuttering is back. Using steam overlay, you can see in the garage that fps drops below 60fps.

First I thought the fps was limited in garage view, but the few times it works, the garage fps is close to "in garage" view so to say.
(according to steam overlay fps)

it is a bit sad that a sim that do have so many nice features don't manage to support an SLI configuration
in an solid way when all other games/sims have no bigger issue with it.

(and yes, behavior is the same using dx9, i''m having 72 hours in the game now and less than 10 are actual game time...)

 

Are you aware that DX11 fullscreen goes borderless sometimes and that you must alt-tab to get back in fullscreen mode ?

 

As Ari mentioned, it might be due to the bug with fullscreen not actually running fullscreen. This happens to me when I click on desktop after I clicked on start single player button. If you avoid clicking anything on your desktop after you clicked start game button, then it should maybe start in fullscreen.

 

Hi Ari, I tried the alt+tab trick to get fullscreen and it leads to black screen... then rf2 crashed... back to desktop with a message from windows (7/64) telling me that there was a problem with rf2 and that at next start it will start with other parameters... unfortunately at next start it didn't solved anything... really bored now...

 

What is this magic?

First I tried alt+enter (made no difference) but then I actually did what you suggested, alt+tab and then back to rf2.
That actually made it go back to previous 120fps state without stuttering even when started in "slow motion mode".

Thank you!

@stonec, i have read about that behavior so I never click anything after rf2 has started.

 

Are you running dx11 and SLI as well?

 

If you are in DX9 rFactor 2 crashes but it should work in DX11.

 

No DX11 at the moment, running DX9 with SLI.