Performance in VR is too low, what is wrong

[kunterbunt]

Due to poor performance in VR in combination with Deferred Rendering I investigated to find the bottleneck in my system.

All test where conducted using the standard VR settings for DCS and parking hot in the F-18 in the Persian Gulf map.

 

 

The results are strange.

My results in VR show that although my GPU is only running at 63% (basically not busy), I cannot get higher FPS than 30.

My GPU does not seem to be the bottleneck. So, it probably is the CPU, which is running 2 cores full power. Sounds logical.

 

 

 

My results in 2D show that although my GPU is only running at 58% (basically not busy), I get 51 FPS.

 

 

Why is it possible to get 51 FPS in 2D if the CPU is the bottleneck?

If my GPU is not busy in VR, it should also be possible to get 51 FPS.

Why can't I get 51 FTP in VR? What is the actual bottleneck, as it does not seem to be the GUI or CPU that is limiting me to 30 FPS in VR.

 

 

Any advise? I would get a new computer, if it would help, but I'm not so sure about it, as both CPU and GPU are not the limiting factor.

I'm also a bit disappointed by performance increase in CPUs in the last 5 years.

[RuskyV]

What do you have your pixel density set to in game? Are you using MSAA and at what level?

 

The two biggest frame killer's are PD and MSAA, you need to trade with these two settings to get the best looks vs performance.

 

I would also sugest that you set the power profile of your gpu to "prefer maximum performance". As any other setting will try to dynamiclly adjust the core speed of the GPU and this plays havoc with ASW.

[kunterbunt]

What do you have your pixel density set to in game? Are you using MSAA and at what level?

 

The two biggest frame killer's are PD and MSAA, you need to trade with these two settings to get the best looks vs performance.

 

I would also sugest that you set the power profile of your gpu to "prefer maximum performance". As any other setting will try to dynamiclly adjust the core speed of the GPU and this plays havoc with ASW.

 

 

Thanks (504)Blade. PD is set to 1.3, but I suspect that GPU load would have been 100% if that is the limiting factor.

Concerning MSAA, I used standard VR settings (push the VR Preset button), so MSAA is Off. I attached my settings now. They apply for 2D and VR.

I always check if my GPU is set to "prefer maximum performance", as once after an update it was back to normal.

 

 

But, all these tips help only if my GPU is the bottleneck, which it is not, as it is idling at about 60%.

[Cibit]

I found that until I replaced my ageing rig with my new one the GPU usage was low. Having a more powerful CPU allows my 1080 to run at between 97 and 99%. Before that had similar returns to yourself.

I found that the new OB is smoother for me in VR than the previous build.

 

Have you tried with medium shadows dialled down to flat ?

Edited June 1, 2018 by Cibit

[lemoen]

If you have 2 cores running at 100% then you have your answer. Your CPU is running as fast as it can already. Reduce things that causes CPU load -> view distance, shadows, mirrors.

[BitMaster]

If you have 2 cores running at 100% then you have your answer. Your CPU is running as fast as it can already. Reduce things that causes CPU load -> view distance, shadows, mirrors.

 

^This

 

Watch each core, if ONE of them tilts, that is your bottleneck.

 

The OB is by far smoother btw, try that before you waste time trying to fix things you cannot fix on your end, like RAM usage with the stable release. With 16GB you will encounter problems as it eats RAM like cookies

[kunterbunt]

If you have 2 cores running at 100% then you have your answer. Your CPU is running as fast as it can already. Reduce things that causes CPU load -> view distance, shadows, mirrors.

 

Why would CPU be a bottleneck in VR at 30 FPS but in 2D at 51 FPS?

Anyhow, I switch off all shadows (why would that be CPU intensive?) and moved view distance to minimum. Morrows where already off (why would that be CPU intensive?).

 

Result: same as before. No change what soever. 30 FPS in VR.

My i7-3770K is about 5 years old, but single core performance is only 33% less than i7-8770K. 33% should only help to reach 40 FPS.

So my question: Does anybody get more than 40 FPS out of VR in DCS?

[Hippo]

Can you try the test I suggest here:

 

https://forums.eagle.ru/showthread.php?t=210356

 

You should get over 30 fps with that. I say this in case there is something odd that may be locking your frame rate - but it does sound, as you say, that you have a CPU bottleneck.

 

I can definitely get over 40 fps in VR (as can others).

 

What is your CPU doing when in 2D?

 

I don't have PG btw - not sure if you're only seeing issues in that theatre?

 

"If my GPU is not busy in VR, it should also be possible to get 51 FPS."

 

That doesn't really follow. You're talking about different resolutions and other overheads in VR - the frame rates are very unlikely to be the same. (assuming the CPU is at 100% in both cases).

Edited June 1, 2018 by Hippo

[kunterbunt]

Can you try the test I suggest here:

 

https://forums.eagle.ru/showthread.php?t=210356

 

You should get over 30 fps with that. I say this in case there is something odd that may be locking your frame rate - but it does sound, as you say, that you have a CPU bottleneck.

 

I can definitely get over 40 fps in VR (as can others).

 

What is your CPU doing when in 2D?

 

I don't have PG btw - not sure if you're only seeing issues in that theatre?

 

"If my GPU is not busy in VR, it should also be possible to get 51 FPS."

 

That doesn't really follow. You're talking about different resolutions and other overheads in VR - the frame rates are very unlikely to be the same. (assuming the CPU is at 100% in both cases).

 

 

Using the recommended settings (MSAA x4, my god) is getting me 34 FPS in Caucasus map.

These settings are not for my GPU. I cannot use MSAA. Using MSAA x 4 with Pixel Density of 1.3 will even limit the main screen FPS to 53. While MSAA off will give me 127 FPS in the main screen.

 

The same test in the Caucasus map with MSAA off gives me 45 FPS. Very happy with that.

 

The same test in the Persian Gulf with MSAA off gives me 30 - 45 FPS. Very unstable frame rate. Looks as if Persian Gulf map will cause unstable FPS through unstable CPU high usage. My GPU is not busy.

 

In other words, it is a Persian Gulf problem. Lets wait and see if it becomes better after release. It is still in early access.

[Strikeeagle345]

Using the recommended settings (MSAA x4, my god) is getting me 34 FPS in Caucasus map.

These settings are not for my GPU. I cannot use MSAA. Using MSAA x 4 with Pixel Density of 1.3 will even limit the main screen FPS to 53. While MSAA off will give me 127 FPS in the main screen.

 

The same test in the Caucasus map with MSAA off gives me 45 FPS. Very happy with that.

 

The same test in the Persian Gulf with MSAA off gives me 30 - 45 FPS. Very unstable frame rate. Looks as if Persian Gulf map will cause unstable FPS through unstable CPU high usage. My GPU is not busy.

 

In other words, it is a Persian Gulf problem. Lets wait and see if it becomes better after release. It is still in early access.

 

did you ever get this sorted? having similar issues with PG map.

[Super Wabbit]

Friend of mine both purchased the Persian Gulf map on the recent Steam sale and we too have noticed significant decrease in our VR performance. Our VR settings are as low as we can get them without making the cockpits unusable.