3 hours ago, Virtual-Chris said:

Yes, but if the primary workload is not multi-threaded as we have here, all those extra cores are sitting around twiddling thumbs. 

My CPU is at 50% Utilization, with one core pegged at 100% while the others wish they could help. My GPU utilization is at 80%. I don’t see a way to solve this problem with hardware... the only thing that will make a substantial difference is to optimize the software to better leverage modern multi-core CPUs. But as it stands, we’re really limited by single core performance, which hasn’t changed much from year to year. 

Ps. What evidence do we have that hyper threading helps immensely? All the evidence would support single core performance is king. If anything is actually threaded in this software, surely 8 physical cores can handle it. Right? Is 16-20 cores going to help at all here? I don’t think so. 

I can send you a photo if you want, but my main core (core 15) is not pegged at 100%. It is at about 75% mostly. And all of my other cores are at about 25-50%. The load is spread magnificently over all 16 cores to be honest compared to other sims. This helps smooth the sim right out. Sure, it could be better, but it could also be worse (other sims). 

37 minutes ago, Ianrivaldosmith said:

I can send you a photo if you want, but my main core (core 15) is not pegged at 100%. It is at about 75% mostly. And all of my other cores are at about 25-50%. The load is spread magnificently over all 16 cores to be honest compared to other sims. This helps smooth the sim right out. Sure, it could be better, but it could also be worse (other sims). 

Sure. Please share. I will have a closer look at my core utilization tonight. I’m also going to try overclocking my CPU tonight to see what effect that has. 

On a semi related note I just got advice that our new $40,000  dual Xeon Gold 6248R genetic analysis server which has been on back order for over 8 weeks due to a CPU shortage is shipping next week. It is not just gamers suffering supply issues at the moment.

2 minutes ago, Glenn Fitzpatrick said:

On a semi related note I just got advice that our new $40,000  dual Xeon Gold 6248R genetic analysis server which has been on back order for over 8 weeks due to a CPU shortage is shipping next week. It is not just gamers suffering supply issues at the moment.

But will it run MSFS? 🙂

24 minutes ago, Virtual-Chris said:

But will it run MSFS? 🙂

lol ... it is setup with two redundant 1200W power supplies to eventually take up to 6 of those $20,000 dual slot A100 cards so it should handle 4 x triple slot 3090's fine,  though the 3090 is sort of prosumer and are not suitable for 64 precision so the system would be pretty useless for genetic analysis with just 3090's in it.   i also doubt you could get all 4 of the 3090's to work with MSFS .

Edited November 13, 20205 yr by Glenn Fitzpatrick

Update on my system performance... (i7-9700K 8Core, 3090, 32GB, 4K,100% scaling)

Tonight I overclocked my 9700K (8Core) to 5GHz all cores.  That tipped the balance back toward the GPU being the bottleneck more often than not.

For reference, my initial settings here are: Ultra on all terrain details (LOD 200).  Wave Quality and all settings below it, which are not important to me are "High".  This is in the 208B.

Here's a typical snapshot of various performance metrics... Note that as I said earlier, one core is doing most of the work here (Core 8 at 92%).  This was consistent.  Strangely, this particular snapshot shows "Limited by MainThread" but that flashes occasionally with the majority of the time now spent "Limited by GPU"

LOD 200 by Virtual-Chris (Junk Photos), on Flickr

I get around 55fps on these settings which is up from 45-50 that I had prior to overclocking the CPU a page or two back.  At least the GPU is back to being the limiting factor most of the time, although clearly the CPU optimization is terrible.

Then I shut down and switched to LOD 4 (400?) in the usercfg file.  As @Ianrivaldosmith suggested, this put more load on the CPU and I was back to being CPU constrained and FPS suffered as a result.

I get around 40-45fps on LOD 400, which is not far off where I was on LOD 200 before the overclock.

LOD 400 by Virtual-Chris (Junk Photos), on Flickr

It is using more cores a bit more, but still Core 8 was taking the brunt of the load, and by no means is the CPU being maxed out.  So when running higher LOD, the CPU and GPU are both not fully utilized to their maximum potential.  It's all software.  RAM and VRAM usage increases at higher LOD.

The difference in visuals is very noticeable.  Here's a side by side of roughly the same part of Vancouver from roughly the same location...

LOD Comparison by Virtual-Chris (Junk Photos), on Flickr

At LOD 200 nothing is being rendered past the lakes in the middle of the frame.  Everything beyond that is completely devoid of features and covered in a flat texture. You would never know there was a major city or two out there.  I really can't do sight-seeing flights without hacking the LOD.  It's an immersion killer to see buildings and complete skylines popping onto the terrain as you get closer.

Then I flew over downtown Vancouver which is a photogrammetry city.  Interestingly, this is much better threaded than the regular scenery.  CPU core utilization goes up considerably, but even then, the main thread is really stalling the GPU.  The GPU is only rendering 20fps and is mostly idle.  This is an 8-core 5GHz CPU here.  

Photogrametry Fly By LOD 400 by Virtual-Chris (Junk Photos), on Flickr

Photogrammetry also has this effect on LOD 200, but you get more FPS. (note the core utilization fluctuates a lot from nearly all 90% saturated as above to what you see here which is probably on the low-end of core utilization when doing a photogrammetry fly-by)...

Photogrametry Fly By LOD 200 by Virtual-Chris (Junk Photos), on Flickr

My conclusions...

CPU is important for LOD and photogrammetry rendering.  This is unlike any other game I own, but then other games I own don't use photogrammetry or offer these kinds of configurable LOD draw distance options.  Unfortunately, the settings that have the most impact on terrain visuals from the air are LOD and photogrammetry.  You can get great FPS by compromising on these two visual settings, but then what's the point of flying around at 60fps if the scenery is popping in under your plane?

I'm still not sure how much throwing more CPU at this problem will help.  It surely does make a difference as my own overclock proves.  But could you throw enough CPU at this game to solve the photogrammetry penalty?

Asobo clearly has some work to do on optimizing CPU usage when not flying around photogrammetry... one core is heavily loaded while other cores aren not... and that one core can be holding up the whole system from rendering more frames. Interestingly though, the Photogrammetry stuff is already fairly well multi-threaded.  I'm not sure what they can do with that to optimize it.

Ultimately, by overclocking my CPU, I've bought myself enough frames to be happy at LOD 4 (400) as I can fly around most places at around 40-45fps.  I'll take 45fps and high LOD rather than 60fps and low LOD.

The thing that will be chewing at me, is how much more performance I can get by upgrading to an AMD 5950X. Ugh.  Before I spend more money, I'm really hoping Asobo can come along with some optimizations to get everyone some free performance gains.

I'm interested in any other's interpretations of this, and other thoughts you might have.  It's the most fun I've had dissecting computer performance in a long time! 😄

 

 

 

Edited November 13, 20205 yr by Virtual-Chris

How much of this guide did you guys find useful?

https://forums.flightsimulator.com/t/how-to-graphics-settings-and-performance-guide-10-29-2020/132407

I just did some of this stuff and some of it seemed to help, but not sure...

 

9 hours ago, Ianrivaldosmith said:

I can send you a photo if you want, but my main core (core 15) is not pegged at 100%. It is at about 75% mostly. And all of my other cores are at about 25-50%. The load is spread magnificently over all 16 cores to be honest compared to other sims. This helps smooth the sim right out. Sure, it could be better, but it could also be worse (other sims). 

Yes, I totally agree.
Same here where the load is nicely spread over all cores.

8 hours ago, David Roch said:

Yes, I totally agree.
Same here where the load is nicely spread over all cores.

You can see that your last core is taking on more of the load... and I expect if you monitored that during flight, you would find it is peaking much higher than most of the other cores and is likely the core running the dreaded "main thread".  Unless you're running a 3090 though, you may not need to worry about becoming CPU limited.  I wasn't CPU limited until upgrading the GPU to the 3090 where it takes a lot more CPU to keep it busy.

9 hours ago, SceneryFX said:

How much of this guide did you guys find useful?

https://forums.flightsimulator.com/t/how-to-graphics-settings-and-performance-guide-10-29-2020/132407

I just did some of this stuff and some of it seemed to help, but not sure...

 

I used that initially, but should have another look at it.

 Someone here recently shared this video which provides great insights into the effect that settings can have on visuals... although he did not test LOD on photogrammetry which is unfortunate.

 

 

Here's an interesting benchmark for comparison...  This guy has a 5950X with a 3090 and he's getting over 60fps in photogrammetry heavy Tokyo.  With my CPU and the same GPU, I'm getting 40fps.  So throwing more CPU at this game will definitely help with photogrammetry.  Hmmm. 😧

https://www.youtube.com/watch?v=xxcTRDFivLA

 

Edited November 13, 20205 yr by Virtual-Chris

10 hours ago, Virtual-Chris said:

Here's an interesting benchmark for comparison...  This guy has a 5950X with a 3090 and he's getting over 60fps in photogrammetry heavy Tokyo.  With my CPU and the same GPU, I'm getting 40fps.  So throwing more CPU at this game will definitely help with photogrammetry.  Hmmm. 😧

https://www.youtube.com/watch?v=xxcTRDFivLA

 

Same here, around 60 there too. Like I say it seems hyper threading make a big difference. 

10 hours ago, Virtual-Chris said:

Here's an interesting benchmark for comparison...  This guy has a 5950X with a 3090 and he's getting over 60fps in photogrammetry heavy Tokyo.  With my CPU and the same GPU, I'm getting 40fps.  So throwing more CPU at this game will definitely help with photogrammetry.  Hmmm. 😧

https://www.youtube.com/watch?v=xxcTRDFivLA

 

But he is using Cockpit Refresh Rate at Medium, that will give him 5+ fps at least, personally I think the game is unplayable with Cockpit Refresh rate at other than High as I hate jerky instruments.

12 minutes ago, Ixoye said:

But he is using Cockpit Refresh Rate at Medium, that will give him 5+ fps at least, personally I think the game is unplayable with Cockpit Refresh rate at other than High as I hate jerky instruments.

Out of curiosity (as I have no clue), how quick do those instruments refresh in real life? 

2 hours ago, Ianrivaldosmith said:

Out of curiosity (as I have no clue), how quick do those instruments refresh in real life? 

The G1000 is a 1024 x 768 display but no idea what it's refresh rate is.