90hz/60fps or 60hz/60fps for VR ?

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Hi there.
I'm new to VR, i have an Acer Windows MixedReality headset, a RX570 8Gb and i5 4590 processor.
My spec can run solid 90fps in practice mode (alone on the track) but when it come to race, the maximum stable it manage to maintain is a solid 60 fps (full grid) and i've already spent a whole week trying to optimize thing with parameter and even with oveclocking my graphic card.
As WMR owner already know, the WMR steam VR motion reprojection is a complete garbage, not only producing lots of artifacts (ghosting etc.....) but also lots of stuttering and even 1sec lag sometimes, wich make motion reprojection not a option for me.......
SO my question is if i can get stable 60 fps, do I need to reduce the headset to 60hz, or just let it at 90hz ? the main reason is of course to reduce possible motion sickness.

Thanks !
 
That is the whole problems with humans and computers, from what I think is good and what on my system runs great, could be the opposite in your situation.
Why not test it by yourself, by using a race track that has an high speed curve like the old Monza or an oval like Daytona in combination with a rally/hillclime track in the mountains. I can sure tell you, will now experience the best settings if being afraid of motion sickness.
Also test check/uncheck fixed horizon and read @Andrew_WOT VR manual, think it is an handy for your search.
 
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I'm already using RHM for horizon locking ! what i want to know is :
is it more safe (motion sickness regarding) matching the 60 hz refresh rate with 60 fps or keeping the 90hz.
One thing stupid that i discovered yesterday was : With exacly the same setting but just turning off WMR motion reprojection i can hit 60-70 fps in average, which normally mean that with Motion reprojection enable, i would be lock to 45 fps with no problem at alll but no, on i turn it on it has an average of 43 fps !!!!! WTF .......
 

RasmusP

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If 60 fps at 90 Hz is really working, you'll see stuttering and screen tearing. Which in VR would be hugely strange.
So if you are not seeing this, I think you actually run 45 fps but the fps value is incorrect.
Or the headset is running at 60 Hz without you knowing.
 
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Yes when i put it to 90hz, it seems not fluid compared to 60 hz with exactly the same FPS but not as bad as WMR motion reprojection but it is like playing game in normal screen with 25 fps. In 60 hz it is a lot fluid but in the two case i have little motion sickness ....... It is really strange that i can run steady an stable 90 fps in LFS with full scale AI (15 car) and cannot with AC (even not AI but just online car). I was always thinking AC is the most optimised for VR. I cannot hit 90 fps even with all setting turn to low and off in full grid race ....
 

RasmusP

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Yes when i put it to 90hz, it seems not fluid compared to 60 hz with exactly the same FPS but not as bad as WMR motion reprojection but it is like playing game in normal screen with 25 fps. In 60 hz it is a lot fluid but in the two case i have little motion sickness ....... It is really strange that i can run steady an stable 90 fps in LFS with full scale AI (15 car) and cannot with AC (even not AI but just online car). I was always thinking AC is the most optimised for VR. I cannot hit 90 fps even with all setting turn to low and off in full grid race ....
That's normal. Both things.
For VR you need CPU, CPU and CPU... and especially Single Thread Performance!
LFS seems to be a lot lighter on the CPU or better split to multi-threads than AC.

You should grab "openhardwaremonitor" or msi afterburner or something similar to check your Graphics Card Load when playing. If it doesn't reach 95% or higher, your CPU is limiting, not your graphics card.
If that's the case you can set the settings to as low as possible... for AC only shadows, reflections and a little bit the world details and post processing takes some CPU load but overall.. You can't do much, sadly.

You could sell your CPU and buy either the i5 "k" or i7 "k" form your 4xxx series and overclock it to the maximum.
Your CPU only turbo-boosts up to 3.7 GHz, but for AC you would need the "k" processor at 4.7+ GHz overclocked.
But even the i7 4790 overclocked to 4.9 GHz won't allow 24 cars on the grid...

What you could do in AC: disable ALL HUD apps! That will gain you quite a lot :)

For the 60 Hz, 90 Hz and the different FPS values have a look at my video:
It's recorded with my phone in 120 fps and then slowed down to 60 fps (50% slow motion). You'll see the Hz-Counter from my Monitor during the first few seconds. FPS are set to 66.6667 fps to replicate your 2/3 to 3/3 values: 60/90.
You will see the tearing border crawling over the pendulum disk every now and then.
 
The 470 and your CPU is on the lower limit for AC running at an decent level of play. I guess if you run with the 15 AI cars the CPU cores has been loaded to max. You can use the in-build Windows performance monitor to check this for each core.
Please wait for @Andrew_WOT reply, I’m at my holiday in Germany near the Nurnberg ring, so I’m a little bit limited because of my phone.
edit: I hope he will include his VR manual, start with his advised lowest settings.
 
I'm already using RHM for horizon locking ! what i want to know is :
is it more safe (motion sickness regarding) matching the 60 hz refresh rate with 60 fps or keeping the 90hz.
One thing stupid that i discovered yesterday was : With exacly the same setting but just turning off WMR motion reprojection i can hit 60-70 fps in average, which normally mean that with Motion reprojection enable, i would be lock to 45 fps with no problem at alll but no, on i turn it on it has an average of 43 fps !!!!! WTF .......
Do a test without the locking as some are feeling, like me, more motion sickness, as I wrote down what for an other forum member could be right, could be for you resulting in the complete opposite effect. You have to figure this all out by your self, we can only advice on what is working for us.
 

RasmusP

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the CPU cores has been loaded to max. You can use the in-build Windows performance monitor to check this for each core.
This sadly is not true at all. AC only runs on 2-3 CPU threads. Windows splits the load across all CPU cores though. So what happens for 1 application thread is:
- Core 0 to 100% for one clock-cycle, Core 1 caching
- Core 1 to 100% for one clock-cycle, Core 2 caching
- Core 2 to 100% for one clock-cycle, Core 3 caching
- Core 3 to 100% for one clock-cycle, Core 0 caching

It's not accurate but you can imagine it like this. What you see in all hardware monitors, including windows own tool is the averaged load. But an application running on 2 threads means a maximum of 2 cores maxed out at the same time.
The caching and spreading from Windows means a higher load than what would theoretically be possible though.

In the end AC can spike to 100% overall CPU load for a 4-core, 4-threads CPU but the more cores you have, the lower the CPU load you'll see will be, although your CPU is hitting its Single Thread Limit.

For a Ryzen CPU with 12 cores and 24 threads the overall load might only be around 15% although the CPU will already be limiting. While with a 2 core and 4 thread i3 the CPU will constantly be hitting 80-100% overall load while limiting.

I for example have a i7 2600k. 4 cores, 8 threads. My 1% low fps when doing a ~20 car grid race, AI or multiplayer, are about 55 fps in all sims. Apart from AMS. Although my CPU load never goes above 70% on any core/thread in hardware monitors. Only ACC spikes to 90% occasionally.

So I limit all sims at 60 fps (100 Hz g-sync Monitor so I can limit anywhere in the range) and only get slight drops during the start but no stuttering/drops for the rest of the race.

If I limit the fps at higher values it will run fine for most parts but I'll get occasional drops/stuttering at random moments. Since I find that irritating while racing, I rather limit the fps a little lower.
 
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About the cpu, we all agree that mine is limited if i run full grid offline, where my cpu need to calculate each car physics and drive the ai themself. But if i'm not wrong, online race is different, as each car physic is calculated on each player computer, then my assetto corsa just stream an "approximative" position of other player to me.
So i think the issue is gpu related.
And as opposed to what you said @RamusP LFS use way more CPU than GPU .....
This is what is written in LFS minimum requierement :

Minimum computer requirements:
2 GHz CPU, 256 MB memory, DirectX 9 capable 3D graphics card.

Recommended computer requirements:
3 GHz CPU, 1024 MB memory,
3D graphics card with at least 512MB memory.
LFS is mostly CPU dependent due to its physics calculations.
A full multiplayer grid requires a fast CPU more than a fast GPU.

LFS will run on Microsoft Windows XP or newer.

And as strange as it can be i found LFS graphism way more realistic in VR than RF2 or AC at very low setting, i don't event talk about their "real mirror" and LFS run 90 fps stable .....
 
@RasmusP You are right about that, it shows only average core loading, but I still think in the TS case his cores will be full loaded. The i5-4950 runs at 3.3Ghz and 3.7 in Turbo, if running VR that is way to low. It does not only handle the game but also the VR calculations on top of that.

But very interesting is that AC runs at 2-3 cores did not know that. Any knowledge if you separate one core pure for Window tasks and 3 cores only dedicated for the AC game & VR?
Once I did play an nonVR combat flysim game called “wings over Flandres fields” that was pure single core based, while using the method above, I could play this game without the usually frame drops. ( locked to 60FPS on my 60hrz monitor, no Vsync).

edit and what about pulling inn the HT cores for AC-VR, as now I have disabled that.
 

RasmusP

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@RasmusP You are right about that, it shows only average core loading, but I still think in the TS case his cores will be full loaded. The i5-4950 runs at 3.3Ghz and 3.7 in Turbo, if running VR that is way to low. It does not only handle the game but also the VR calculations on top of that.

But very interesting is that AC runs at 2-3 cores did not know that. Any knowledge if you separate one core pure for Window tasks and 3 cores only dedicated for the AC game & VR?
Once I did play an nonVR combat flysim game called “wings over Flandres fields” that was pure single core based, while using the method above, I could play this game without the usually frame drops. ( locked to 60FPS on my 60hrz monitor, no Vsync).

edit and what about pulling inn the HT cores for AC-VR, as now I have disabled that.
For me, hyperthreading gives higher fps im AC.
The flight sim example is interesting. Normally you only lose fps if you lock an application to certain cores because you lose the performance increase from the caching and spreading.
But some certain applications might not be made for any multithreading at all and might run better if you put it on one core only.
I never came across a game that works like this yet!

Only cases where this gives a better performance would be if you have single core boosting on your cpu that is too slow when constantly changing the loaded core.
Example:
Core 0 boosts to 4.3 GHz, core 1 runs at 3.5 GHz.
Now windows puts the application to core 1 but core 1 can't boost to 4.3 GHz in time and core 0 can't clock down quick enough.
In this case it would be better to lock the application to core 0 and let it boost constantly.

I'm not sure how quick the 4xxx series can boost. I only know that the new ryzen can boost a lot faster than the previous generations and now the locking defitely means lower fps!
Also with my all-core-oc on my I7 2600k I lose fps if I lock applications to cores or disable hyperthreading.

However you might run into core parking if you have too many cores compared to application threads. I disabled core parking completely.
Also some games produce stuttering when ht is on. Battlefield 4 (and also bf 1 at some patch stage) are the only examples I personally experienced to do this though.

Just if we misunderstood:
Just because his cpu is too slow to be capable of 90 fps the maximum overall load that is possible with the low amount of AC threads won't change. Only the fps value that results from it.

BTW, you can read out the amount of threads via "process explorer". Little tool where you can go into the properties of an application and see all the threads. The numbers mean cpu percentage.
One single thread can only reach the result of "100 devided by cpu threads". It barely does though. Mostly the limit is reached at a little lower values.
In my case 12.5 %. Ac has 2 threads reaching more than 11% and a third thread reaching 4-8%.
The additional VR cpu load goes on top of the first thread. Directly lowering the fps when in the cpu limit since there's no headroom even without VR!

In theory this would mean ac producing a maximum of 30% overall load.
But due to the spreading etc from windows I reach 50-60%.

If you'd lock ac to 3 cpu threads though, you would only get 37.5% overall load.


A completely different example is F1 2018 and 19. There you'll see a lot of threads with none of them going above 9% for my cpu. Resulting in the cpu limit being at 100% overall load.
It can truly max out my cpu.
However.. In fact it can't. I tested F1 2018 in the lowest Reduktion possible and the fps just got stuck at around 180 fps while not hitting 100% cpu.
I guess there's either a memory limit or simply a game engine limit. But who needs more than 180 fps anyway...
 
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My CPU load is almost 95% (but it isn't specified per core, just overall) when i run the kunos benchmark with 15 AI but i think the benchmark is just a replay not real ai since the car drive exaclty the same each and every bench. and if i run real race the same track with the same number of ai on the same setting the performance is hugely worse. in the other hand, on online it only drop a very little fps on the average but a lot when for exemple a massive number of car crash .....i've force my LOD of all other car to minimum all the time ....

Edit : i found largelly better performance using WMR Steam VR reprojection when my fps is locked and steady 45 and when i force motion reprojection all the time (no auto) but the thing is i cannot get it unless i turn SS to 20% ... even on 60% wich is the same native resolution as the rift CV1 (1200x1200) i'me getting 43 average wich doesn't make anysense cause the same setting can handle +/- 70 fps when the motion reprojection is off .........

I found on steam forum that WMR motion reprojection has issue with game with multiple layer rendering such as PC2 so i turned off mirror in case of but it doesn't change anything....

This thing is getting very strange ......
 
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Andrew_WOT

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Reprojection has performance issues a the moment, when it works it is the best implementation you can find, hardly any artifacts. If you can't get 90 fps out of your system by lowering visual settings, try 60hz refresh rate. It will have some flickering, not that bad, slightly lower FOV (mostly vertical), and lower default SS resolution, which you need to increase to match 90hz quality.
Until MS fixes repro, I'd keep it off.
Good luck.
 
About the cpu, we all agree that mine is limited if i run full grid offline, where my cpu need to calculate each car physics and drive the ai themself. But if i'm not wrong, online race is different, as each car physic is calculated on each player computer, then my assetto corsa just stream an "approximative" position of other player to me.
Sorry to interrupt, but is that true?
Before last month I used to have i5 2600K with VR (yeah, yeah I know...). If I was driving at Nordschleife offline with AI I managed to rich my 45-50 fps but never 99% cpu loading warning. When online and driving together with 3-4 cars in visible range this warning was guarantied. But it more often appears only when opponent's car is being at some maneuvers like hard turning or drift or getting slip etc. So for me looks like AC calculates opponent's car physics at my machine. Or at least a part of it. maybe.
 

Andrew_WOT

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Different things. AI physics calculation, which is the same as on flat screen, and not that tasking on modern CPUs.
There is also rendering thread, and this is a completely different beast in VR, as it needs to calculate each scene twice and in decreased frame time, with 90 fps you have only 11.1ms for both CPU and GPU to complete its works. The more visible AIs you have, the harder it is for that single thread to keep up with the load within this time constraint.
 

RasmusP

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Sorry to interrupt, but is that true?
Before last month I used to have i5 2600K with VR (yeah, yeah I know...). If I was driving at Nordschleife offline with AI I managed to rich my 45-50 fps but never 99% cpu loading warning. When online and driving together with 3-4 cars in visible range this warning was guarantied. But it more often appears only when opponent's car is being at some maneuvers like hard turning or drift or getting slip etc. So for me looks like AC calculates opponent's car physics at my machine. Or at least a part of it. maybe.
AI physics are there and they are important for the cpu warning and the logic of the game but if you do 24 AI vs 24 cars online the physics will only make a small difference.
Like 100 fps online, 90 fps with ai.
The bigger part is the rendering. Drawcalls, movement of the objects etc etc like Andrew said.

You can spectate this in ACC pretty easily.
Lower the resolution, run a full grid of AI cars and test the fps your cpu can run at.
Then you put the visible opponents to 1 car and magically you'll have doubled your fps.
The physics are still running in the background, since the car is still there. It's just not visible for the rendering.

You'll see the fps increasing when you run less AI cars but it's nothing compared to the amount of fps you'll gain when lowering the visible cars.
 
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So i tryed the whole night new setting and found a miraculous fps saver :
In the custom shader patch setting, i lower the "far clipping plane" wich by default is 20 000 / 30 000 to 2000 /3000. so now with the assetto benchmark i have 80/83 fps on the grid start then directly get steady 90 fps past eau rouge (spa) and all the resting track. i just resulting a visible clipping plane but only on long straight but i largely prefer 90fps instead of seeing tree in 30Km hahahah ! My configuration was :
82% steam supersampling which is the native (1440x1440) cause 100% is 16XXx16XX which is then in reality 120% density.
4 x AA
8 x anisotropy filter
smoke generation to minimum
1024 x 1024 shadows resolution
512 x 512 static reflection
Post processing on but on minimal and without glare (cause glare cost 2% of fps)
Normal assetto mirror with minimum resolution (Real mirror and smart mirror disabled in shader patch)
I've also change the lod threshold in shader patch "graphic setting" to minimum and change post procession anti aliasing to the Nvidia MSAA 2015 thing.
in assetto bench My GPU usage is 100% all the time and CPU is between 54% to 60% maxi.

I was very happy cause i had hit 87 average fps the whole track and 90 stable fps 95% of the track, only had frame drop on start. So i decide to run offline race with 14 AI, the same cars, and the same track (spa) as the bench. It struggle to get 50 fps but i was aware cause i know assetto bench is just a replay and not real AI, so i jump in online with lot of hope but cry after seeing it has the same performance as the onfline race :
30 to 60fps maxi with 18 opponent, single openwheel car "tattus", and monza. And i don't even race, just join the qualifying session whith already spread car.
My CPU load jump to 93-100 % usage and GPU still 100% all the time, ram usage is 6GO with chrome running in background.

So i really don't know what is the problem ...... it seem the cpu but if it was cpu who bottleneck the gpu, my graphic car will not run on 100% right ?
 

RasmusP

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So i really don't know what is the problem ...... it seem the cpu but if it was cpu who bottleneck the gpu, my graphic car will not run on 100% right ?
If the gpu is at 100%, it's the limiting factor, yes.
But if the cpu is almost hitting 100% too, it's basicly also hitting its limit because Assetto only runs on 2.5 threads and isn't able to max the cpu constantly out to full 100%.

I'm sorry to say this but your pc as a whole is just not able to run assetto at 90 fps, apart from in a replay.
Your cpu would need another GHz, which isn't possible without a "k" cpu and your graphics card is just not powerful enough for assetto in VR :(
 
A ingame benchmark is normally not that demanding for hardware.

As I did wrote earlier your whole PC is on the low site for playing AC-VR, so I would drop everything to lowest maybe this by 2019 standards low-end 470 can now cope AC a bit in VR.
Stop every not being used process/services, not needed software, like a virusscan while not being on the internet, this could relieve your CPU.
 
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