Afternoon everyone,

Post WU14 I appear to be suddenly limited by my main thread. I am not totally convinced this has occurred in conjunction with WU14 as no one else appears to be having such issues. I have not had an issues with main thread limitation before and I have tried a variety of things to fix it, all detailed below.

Firstly, my PC Specs are: i9-9900KF CPU, 32.0 GB RAM, GTX3080 NVIDEA Graphics Card

For a routine flight I nearly always fly the Fenix a320 with the following add on's/background apps. Volanta, Pegasus (ACARS), FS Realistic, Self Loading Cargo, GSX, FSLTL or VPilot (vatsim). 

My GPU will rarely exceed 50% usage and RAM usually sits between 60 and 80% usage. 

Now for the 'strangeness'. With all the above apps not in use and not running, with terrain/object LOD turned down to 10 and all traffic set to 0 I am still only pulling 40fps at Maccosim's EGCC. 40fps is of course absolutely fine however, not very immersive with everything out the window from up high looking poor.

Screenshot: https://ibb.co/PTxKjs7

Prior to WU14 I was able to have the terrain LOD sit at 175 and the object LOD at 120 and still pull through a healthy 33FPS. Post WU14 with these settings I am pulling 22-25FPS and this is without the above apps running. With the apps running I am then down to 20-22FPS which is on the cusp of making the aircraft unflyable.

So what have I tried. I have scanned my PC for malware which was negative. I have updated my PC's policy and attempted to close down any background processes/apps however, this has made no difference. I have not made any 'tweaks' or otherwise to my PC prior to or since WU14. This has very much come out of nowhere.

If anyone is able to help I would be much obliged 😀.

Most people with a good graphics card will show as being limited by main thread.  I have a 13900k and it still shows it.  You have to have a limiting factor somewhere (the resource that is struggling the most), and unless there is a specific problem with the PC or a really old graphics card, it will always be the main thread. 

Mine shows two CPU threads topped out at 100% actually, but I am pushing it (4k ultra 60Hz with LODS around 150), and as you say, my 4080 is barely breaking into a sweat as well.  50% and 50C.

After saying this, some people have seen some gradual but slight performance degradation again over recent updates. 
I seem to have noticed it also, as my main threads on the 13900 seemed to be running at 85-95% when I first bought the chip, but just lately they are flat lining at 100%.

DX12 in SU13 beta isn't the best either at the moment, so not sure what has happened there, but it is a beta I suppose so plenty of time to fix it.

I know it isn't the answer, but MS / Asobo claim they will make this better in MSFS2024 by making it a lot more multi-threaded, and they say they are seeing massive performance improvements, especially with their new 'graphics system', which is hopefully a full optimised DX12, not a basic conversion like we have now with a few bugs and no real advantage other than if you have a card capable of frame generation.

I would have liked a round of performance optimisations in the sim again, but with 2024 on the horizon, I can't see them putting any resource into it, as it is one of the main selling points of 2024, so they wouldn't want to undermine that too much.  

Edited August 14, 20232 yr by bobcat999

Hi Rob,

Interesting you are also seeing some performance degradation. I had not noted this on the forums post WU14. It is frustrating as I can not fathom the cause. I am unable to take any further stress off the CPU and the PC is still having a tough time of it.

I am hopeful 2024 will bring further optimization but we shall just have to wait and see!

9 minutes ago, NicXGG said:

Hi Rob,

Interesting you are also seeing some performance degradation. I had not noted this on the forums post WU14. It is frustrating as I can not fathom the cause. I am unable to take any further stress off the CPU and the PC is still having a tough time of it.

I am hopeful 2024 will bring further optimization but we shall just have to wait and see!

Yes.  I really don't think it is anything at your end, and you can waste hours chasing your tail, like I have at times, but ultimately, the main thread does take a pounding in MSFS, and not much you can do about it. 

It is what it is, and I can get by with it.  I daresay you will get a few people say 'well mine is alright', but different people have different expectations.  One guy on here a while ago said he was happy with his setup - turned out he was running at 20FPS but was happy with it!    It takes all sorts.

Edited August 14, 20232 yr by bobcat999

@NicXGG  You forgot to mention your screen resolution actually Nic.  Strangely enough, with something like a 3080 like yours, increasing screen resolution can actually help the CPU, for technical reasons I don't fully understand!    But people like Gamers Nexus and LTT do test at lower resolutions to put more strain on the CPU for some reason.

Also, the main factors that seem to affect my CPU load are, obviously the LOD settings that you mention, complex airports, and AI traffic. 
Surprisingly, although a lot of these seem related to graphics, the CPU has a hell of a lot of load to carry with them.

Complex aircraft don't seem to affect the CPU that much for me.  The PMDG 737's and the latest A2A Comanche don't seem to be a problem, and although I haven't tried the Fenix A320 yet (I will soon), apparently the optimisation has gone well on that and it is up there with the PMDG stuff.

Are there any particular aircraft you are flying in the sim?  There are a few oddball ones that seem to lack optimisation and bring the FPS down a bit, normally when they are using a lot of custom gauges that maybe aren't optimised too well.  The Kodiak for instance had a problem with the standby gauge a while ago - not sure if it is fixed now.

EDIT:  I just saw you are in this scenario... "For a routine flight I nearly always fly the Fenix a320 with the following add on's/background apps. Volanta, Pegasus (ACARS), FS Realistic, Self Loading Cargo, GSX, FSLTL or VPilot (vatsim)."

 Obviously, GSX and FSLTL (depending on settings) will pinch a bit of your CPU.  I have Maccosim Manchester that you use and it doesn't seem too bad on performance.

I would say, with all that running Nic, you are not doing too badly!  

Edited August 14, 20232 yr by bobcat999

What about Asobo's A320 @ default EGCC?

You killed the external software but you are still using heavy aircraft and airport addons. Are they updated to the latest versions? I was reading that Fenix has improved its framerate a lot in the last version, check it out. 

I cannot check for you because I don't have these addons, but I haven't experienced any performance loss since WU14. 

@bobcat999 Just had a ticker with the screen resolution which was set on 2303x1295. I changed this up to 3263x1825 and I have definitely gained another couple of FPS. Also getting a little more use out my card. It's now sat at 65% which makes it more value for money 😂.

The Fenix is very performance friendly and V2 Block 1 is even more generous than before. I have lowered my FSLTL settings also however, this has had very little impact.

@MrFuzzy Just did a little more testing. With the default a320 and with all the above addons running I am seeing 30fps. With the Fenix V2 I am seeing 21/22 fps after making a few more adjustments. All scenery and aircraft are up to date.

It just seems I should be getting a little more out of the CPU than I am.

Well, I wouldn't say that the Fenix is performance friendly if it lowers your framerate by 25-30% after "adjustments" with respect to Asobo's A320 and the same addons...

With Asobo's aircraft, default airport and without FSLTL, I bet that your framerate would be around 40-45 fps with TLOD 200 and your GPU fans would start spinning happily 🙂

Unfortunately these addons are heavy and the 9900K is quite old. I think that what we are seeing here isn't new and there's not much to investigate, really...

P.S. Just one more thing: what frequency is your RAM running at?

@MrFuzzy I'd say compared to the other add on airliners it is very performance friendly. I own quite a few and can say this is the most generous of them all.

I believe you are missing the point of the post. These issues have come about very recently and my 'old' 9900K (which is not 'old') was handling everything brilliantly. Add on scenery, aircraft and all.

Thank-you for your input. 

Just out of curiosity, have you tried optimizing your settings with nVidia's GeForce Experience app? I use the recommended settings, or something fairly close to them, and they seem to work fine. Just something to try.....

3 hours ago, NicXGG said:

If anyone is able to help I would be much obliged 😀.

Folks here are suggesting your CPU is old, concerned about RAM (?!), and suggesting it's nothing on your end.  Ouch, you've had a substantial change in performance, and there is no good explanation being provided here.  Can you retest with another high end plane and see where is stands?

For starters, you'd be much better served to LOWER Terrain LOD to 100.  Visually, the difference is paltry.  Next, increase Object LOD to 200 as it has almost zero impact in the main thread, whereas with our CPU T-LOD absolutely does.

Next, get out of the mindset that frame rate is the issue.  Instead, consider this methodology to achieve ultimate smoothness at modest frame rates.   We have essentially identical hardware and I have incredibly good performance defined as subjectively ultra smooth animation w/ little to no stutters anywhere in PMDG 738, FBW 320NX and others.  ALL my settings are at Ultra, save T-LOD which is where most of the load on the main thread happens.

https://www.avsim.com/forums/topic/628655-ultimate-smoothness-at-modest-frame-rates/?do=findComment&comment=4899096

 

@jrw4 Definitely worth a try! At this point I'll give anything a go! I'll let you know the results. My only feeling is that this may only look to optimize the GPU and not the CPU. But got to be worth a shot.

@Noel Thanks for this. I will retest with the FBW a320 as that is considered performance heavy in comparison to the Fenix. While I am looking at the fps I am also conscious I am just chasing that smoothness over the number. For me, sitting at 25fps is manageable with little in the way of stutters. I will also lower the T/LOD and report back with the findings.

10 minutes ago, NicXGG said:

For me, sitting at 25fps is manageable with little in the way of stutters.

I guarantee you will be well over 25fps, everywhere, unless there is actual hardware/driver issues behind the degradation.