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FPS drop when using FS Labs

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Hello,

I have noticed that when I use the FS Labs aircrafts I see a significant drop in FPS (with Prepar3d v4.5). When I use PMDG or QualityWings the FPS is a lot higher (with exactly the same settings).

Has anybody else noticed the same? Are there any specific settings that can be applied to FS Labs to make FPS similar to those of PMDG or QW?

Thanks in advance.

So I bought it yesterday and completed my first flight with it.

At first my FPS was pretty poor, this is a very intense simulation on both your GPU and your CPU. The main tip I have (which I found in a thread on here) is to use your NVIDIA control panel (or whatever the AMD equivalent is) to set the target FPS to something reasonable, say 30-35 FPS and make sure the slider in P3D is set to unlimited. I don't know why this worked so well for me but it did.

My specs are:
i7 9700k
RTX 2060 6GB
32GB RAM

I went from ~20FPS at the airport and 35FPS in cruise, to around ~35FPS even at EGLL and 60FPS in cruise (not sure why it went so far over the target frame rate but frankly not bothered).

Obviously it's dependent on your specifications but it worked for me, might work for you also?

  • Author

Thanks for your reply and suggestions.

I have a very similar PC: i7-9700k (3.6GHz), RTX 2080, 32GB RAM.

In NVIDIA Control Panel I have increased the 'Max Frame Rate' to 250, set the 'Power Management Mode' to Max Performance, and 'Preferred Refresh Rate' to Highest Available. Despite this I get the following average FPSs (with Active Sky connected):

PMDG 747-8:

LEBL (with Aerosoft scenery): Cockpit 49fps, Exterior 100fps, RAM usage 34%. EGLL (default scenery): Cockpit 27fps, Exterior 53fps, RAM 34%.

FSLabs 321-SL:

LEBL (with Aerosoft scenery): Cockpit 30fps, Exterior 43fps, RAM 44%. EGLL (default scenery): Cockpit 19fps, Exterior 30fps, RAM 44%.

In all the above cases CPU goes to 4.57GHz with an average of 33% usage.

With FSLabs the resolution always decreases, even with the changes on the Nvidia panel. I also cannot understand why having 32GB RAM, its usage always remains way below 50%. Having so much RAM, wouldn't it make sense to use a higher percentage?

Thanks anyway. I will keep researching the reason for this.

Do you have Hyperthreading enabled in the BIOS? If so you need an Affinity Mask setting in prepar3d.cfg. How many logical processors does your CPU have?

If your monitor can run at 30Hz use that in NCP and set Unlimited in P3D with VSync enabled.

P3D will run very well with those settings. FSL aircraft are probably hungrier than others so set Scenery Complexity one notch lower.

  • Author

Hello,

1) I have AffinityMask=85 in my .cfg file. I tried to look in the BIOS but I couldn't find if Hyper-threading is enabled or not. 

I have checked the following:

C:\Users\Spock>wmic

wmic:root\cli>CPU Get NumberOfCores,NumberOfLogicalProcessors /Format:List

I see that the Nr of Cores and Nr of Logical Processor is the same, 8. If I am not mistaken, this means that Hyper-threading is not enabled. Should I then remove the AffinityMask=85 setting in .cfg? Or better enable Hyper-threading in BIOS and keep AffinityMask in .cfg? (Not sure how to enable this, although I can look for it).

2) Regarding the monitor, in Nvidia Control Panel I have a Refresh Rate of 120Hz. The maximum is 144Hz and minimum is 60Hz. Should I decrease it to 60Hz?

3) In P3D, VSync is On, Triple Buffering is On and Target Frame Rate is unlimited.

4) I will lower Scenery Complexity in P3D when using FSL. It's not at the maximum level at the moment.

Thanks!

Ramon, it sounds like HT is off so you don’t need to use an Affinity Mask setting. Search for JOBSCHEDULER in your prepar3d.cfg and remove it if present. Try a few flights and see if there’s any change. Good or bad.

Alternatively you could try 255 which would use all 8 cores. This is how to set AM ...

[JOBSCHEDULER]

AffinityMask=255

Try 60Hz. You could also use Riva Tuner SS to set a 1/2 refresh rate to force 30Hz. That reduces the demand on the CPU/GPU allowing higher scenery settings.

 

  • Author

I meant I don't know how to enable HT in BIOS, as I couldn't find HT when I checked earlier today. But I will try to play with AffinityMask, Refresh Rate and Scenery Complexity and see if there are any significant changes.

In any case, it's clear that FSL aircrafts use more resources than PMDG and others.

Many thanks for the advice.

Ramon. Open Task Manager and choose Performance tab. There is a graph for each logical processor. My i7-8086K is a 6 core CPU but as I have HT enabled in the BIOS ot shows 12 logical cores.

That display will show at the bottom how many cores and logical processors you have. If they are the same then HT is off.

Fslabs has always been the biggest killer of FPS since ancient times. No matter how optimized it is, it will stutter more and more.

Just now, Yang Shuo said:

Fslabs has always been the biggest killer of FPS since ancient times. No matter how optimized it is, it will stutter more and more.

Lower scenery settings are required for more complex aircraft. You can’t have your cake and eat it.

11 hours ago, Ramon Alsina Munoz said:

I meant I don't know how to enable HT in BIOS, as I couldn't find HT when I checked earlier today. But I will try to play with AffinityMask, Refresh Rate and Scenery Complexity and see if there are any significant changes.

In any case, it's clear that FSL aircrafts use more resources than PMDG and others.

Many thanks for the advice.

9700k doesn´t have HT

  • Author

Thanks! That explains it.

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