What is causing low FPS

[samisahusky 13]

I built my computer about 2 or 3 years ago gutting out everything and rebuilding from the ground up. I got an Nvidia 2080TI GPU, 32GB RAM @ 2400MHz, Ryzen 3 3900 CPU, ran on windows 10, everything installed into SSD drives (add ons are in separate drives due to the shear volume required but still SSDs). I was getting 20-30ish+/- FPS in the air with lots of add-ons and unlocked windows from the VC on my 2nd monitor. I decided to upgrade the CPU to the Ryzen 9 5900 and upgraded to windows 11. Now my FPS are the same. In fact, I fly with a VA that shows the average FPS on the final flight log and in the PMDG 737-900ER, I got an average of 2 FPS LESS than before upgrading CPU and windows. So where is the bottleneck?

Is it the RAM speed? I'm considering upgrading to 32GB @ 3600MHz but would that get me better FPS? Google gives mixes reviews on if it will or will not.

Is it the settings in P3D or Nvidia? I've watched a ton of videos on YouTube for P3D settings and every one is different than before - not to mention I already run better hardware than them and get half the FPS they do.

What do I need to be looking at to get better FPS? I'm still only getting 14-25 on the ground when landing which is pretty bad for such high(er) end hardware.

Edited June 1, 2022 by samisahusky

[SteveW 1,792]

Is that the 12 core? If you have SMT enabled you have 24 threads (virtual cores) and the P3D v5 Affinity mask settings defaults unfortunately allows main threads to share cores with scenery loading threads which reduces fps sometimes as much as 30%. You can check if there is a slowdown from SMT by turning off SMT and running P3D from there. If you see a higher fps then at least you know core sharing is not helping. However, with SMT off you lose a lot of performance from scenery gathering (and basically hurts all file loading and networking) which reduces the performance especially when you fly along over new terrain - you can see the sim takes longer to load with SMT disabled by several seconds showing that the file loading and scenery/object creation processes are slower with SMT disabled. If that is so, re-enable SMT and apply the proper Affinity settings to get full fps with SMT enabled. In Prepar3D.cfg:

[JobScheduler]
AffinityMask=16777173
P3DCoreAffinityMask=16777173
MainThreadScheduler=0
RenderThreadScheduler=1
FrameWorkerThreadScheduler=2
 

This setup gives you good and sometimes slightly better fps with SMT enabled than when disabled, so I would always use that first of all and then concentrate on checking other settings from there.

 

 

[samisahusky 13]

@SteveW I'm not sure about the SMT setting. Where does one find that?

[SteveW 1,792]

If you run Task Manager and choose the Performance tab you will see cores: 12 and Logical Processors: 24. That will mean SMT is enabled. You enable/disable SMT in the motherboard settings (usually press F2 key during system boot to enter the settings).

[samisahusky 13]

@SteveW I'll take a look. And to clarify, should I try the affinity mask setting first, or disable SMT if active first?

[SteveW 1,792]

Actually I would just leave SMT on and apply the affinity settings I showed anyway because ultimately that gives the best overall performance. But as I said, you can prove if this is an issue by testing with SMT off to see if fps improves, then you can turn it back on and use the affinity setup to equal that fps performance. SMT off saves problems from poor affinity settings and gives good fps but with reduced scenery loading performance, SMT enabled gives better scenery loading but it must have the correct affinity setup to maintain fps.

[blaunarwal 433]

I have an intel processor, with no hyperthreading. In the past HT was always bad and I think P3D5 didn´t change that. I can´t tell what about AMD CPUs but with 12 cores, you have enough cores. I only have 8 in my intel CPU. And HT is always taking performance of your "real" cores. 

What is different, I overclocked my CPU to 4.8 GHZ. So all cores are running this speed all time. I also have a base speed of 3.6 or 3.8 and boost to 4.6 according to intel spec. But flightsims need high clock rates. I have a 3090 GPU, giving me some more adavantage but I think with an overclocking, you should also be fine with the 2080TI in regards of performance. You only have less VRAM than I. 

For overclocking your CPU make sure to upgrade your Motherboard to the latest BIOS. It may have a dedicated OC mod already, which is working fine. Otherwise is Google your friend, finding some hints how to overclock your cpu.

I had some bluescreens with time, at 5.0 GHz and had to get down to 4.9, then 4.8. The CPU gets older I guess. I first had a quality air cooler, which worked sufficient but then replaced it with a all in one liquid cooler. It´s easy to install and gives you maximum cooling to be save. Never use any standard cooler for overclocking. My CPU runs almost 4 years now overclocked and i have a fluent sim which only halts at large airports, when they are loading. But that is better than ever an I fly sims since FS4. 

Dan

Edited June 1, 2022 by blaunarwal

[samisahusky 13]

@blaunarwal I have an MSI MB that does easy overclocking of CPU. While my base is 3.8GHz I think, enabling Game Boost bumps the clock speed at about 4.5-4.75GHz. I've just installed the faster RAM (now 3600MHz) and applied the [jobscheduler] changes listed above. My last flight landed at WSSS (addon by ImagineSim) and I was getting 14-20 FPS on approach and landing with traffic and weather turned on. With the changes, weather and AI still on, a circuit around WSSS showed FPS about 25-35 flying low around the city (1,500 feet) and would occasionally drop to mid teens as I looked around (using Track IR) and with some undocked windows but then back up to 20-35 a second later. On the ground at the gate after landing, I'm showing about 25 FPS. This will have to do for now. I'll play around with some settings later on, but getting 25FPS on the ground at an addon airport, with Active Sky live weather on, and 71 AI aircraft around me, I'd say thats good. It's an improvement from the 14-20 I was getting before the CFG change suggested and the upgrade of RAM speed.

[blaunarwal 433]

13 minutes ago, samisahusky said:

@blaunarwal I have an MSI MB that does easy overclocking of CPU. While my base is 3.8GHz I think, enabling Game Boost bumps the clock speed at about 4.5-4.75GHz. I've just installed the faster RAM (now 3600MHz) and applied the [jobscheduler] changes listed above. My last flight landed at WSSS (addon by ImagineSim) and I was getting 14-20 FPS on approach and landing with traffic and weather turned on. With the changes, weather and AI still on, a circuit around WSSS showed FPS about 25-35 flying low around the city (1,500 feet) and would occasionally drop to mid teens as I looked around (using Track IR) and with some undocked windows but then back up to 20-35 a second later. On the ground at the gate after landing, I'm showing about 25 FPS. This will have to do for now. I'll play around with some settings later on, but getting 25FPS on the ground at an addon airport, with Active Sky live weather on, and 71 AI aircraft around me, I'd say thats good. It's an improvement from the 14-20 I was getting before the CFG change suggested and the upgrade of RAM speed.

I overclock since about 10 years and would never stop doing so. But it´s up to you.

Some may cruzify me for saying this, but I limit fps to 21 inside the sim. So the cpu has enough time to keep up with all the tasks. Of course, you get a more fluent feeling with unlimited but the steadyness is much better at a lower rate and I don´t mind the 21. It looks fluent, it feels fluent, but I think I´m the only one on the globe using this setting. 😉

Also have Vsync on, variable refresh rate. 

I did not change the  [JobScheduler] settings. Just let the sim set it. You can always try the sims settings by just deleting this entry and start the sim again. It will do its best.

Dan

[samisahusky 13]

@blaunarwal While I don't truly mind the FPS at a lower number if it is smooth and looks good, the Aerosoft A330 will not activate reverse thrust if FPS is below 20. This has been a known issue to them for a long time and they have done nothing to fix it, so I don't think they ever will. Until FSL releases their A330, I need to be able to keep FPS above 20 on approach and landing at all times. Therefore, setting FPS limit to 21 would not allow enough of a buffer. For me, it would be best to have the sim set to maintain as high of FPS as possible (while still having some good looking scenery and addons) at all times, regardless of what aircraft I use or location I am flying in.

[Rogen 1,095]

Unlimited internal with 30 Hz vsync monitors are what I use.

The framerate is capped @ 30 fps by the 30 Hz rate of the monitors via the vsync.

If you've got GSync monitors it would likely be smoother since gsync works well down to low levels of fps.

I also run SMT off and overclock to the max I can achieve with reliablity and this is where having SMT off helped as there is less heat generated and well... P3D just seems to work better without SMT (but that could be just because I'm able to maintain a higher overclock with SMT off).

Cheers

 

[blaunarwal 433]

6 hours ago, samisahusky said:

the Aerosoft A330 will not activate reverse thrust if FPS is below 20.

Didn't know that A330 bug. I have only the smaller Airbus from Aerosoft. If this is a problem, you can of course set higher rates. I selected 21, since 20 is 1/3 of my refresh rate and a bit higher will give you some 20.8 fps most of the time. Of course this could be also set higher, at 25 e.g. but then you have more fluctuations, depending on the overall power of the system and the aircraft and scenery you're flying in. 

[CaptKornDog 286]

On 6/1/2022 at 10:01 AM, SteveW said:

[JobScheduler]
AffinityMask=16777173
P3DCoreAffinityMask=16777173
MainThreadScheduler=0
RenderThreadScheduler=1
FrameWorkerThreadScheduler=2

Thank you for this.  Been pulling my hair out trying to figure out the best settings for a 12-core 5900X with SMT for quite some time.  These seem to work nicely.

[samisahusky 13]

Just for updates, I did the affinity mask change listed above, and also upgraded my ram to a higher processing speed. Those changes got me slightly above 20fps in the a330 (average 21.8). However, I've been tracking my average fps for each aircraft I fly and this bird ranks 2nd to last with the capsim 757 being worst (phasing it out sadly). Aside from the a380 all my aircraft are payware. Even in FSLabs a320/1 I get close to an average of 40fps. The average fps is from each flight report shown from my VA. Bottom line, the aerosoft a330 is very heavy on fps, and when FSLabs releases their a330 sometime after year 2953 I'll be switching to it. It likely was not my set up but rather the huge fps demand on this particular aircraft. Still, who codes an aircraft to not give reverse thrust when fps are low when historically fps are always lowest at landing? Seems to be a huge oversight on aerosoft that they have been aware of for years and have no intentions on resolving.