This is not normal behavior if you are running a game as all of your games should be running off of the 1st CCD. Do you have gamebar turned on and your Win 11 power plan set to balanced? If so and you still have this issue then I recommend that you use Revo Uninstaller (free version) to uninstall your chipset drivers and then reinstall the latest AMD chipset drivers.
Having the latest bios is always a good idea however a fairly recent one should be fine.
I took the screenshot while only MSFS 2024 was running. I had completely reinstalled the PC, including the latest chipset drivers and updated the motherboard BIOS to the latest version. Game Bar was enabled, and CPPC in the BIOS set to ‘Driver’. Powerplan was running on balanced. 
By any chance did you take the screenshot from a 2nd monitor? Clicking on another program can take the focus away from the game and cause the game to shift over to CCD1. Your Ryzen Master pic just shows a snapshot in time without any history. Try using just the Windows Task Manager (performance tab) and it will show CCD usage a little better visually.
There are a few things in the sim itself that have a huge negative impact on performance at the moment. Start with no addons, at an airport like EGLL or KJFK. I suggest turning the following down or off and try again:
Without having read all the details in the thread, have you tried absolute stock default settings on everything? Speaking only for myself, I get the best results starting with stock, and then only tweaking 1 thing at time to see the effect, and only if needed.
Also what is your CPU and GPU cooling and temperatures in MSFS?
This summer I built a new PC (first time!) with a 9800X3d and RTC 5090, and decided to just stick with all defaults until I understood it. This was a good strategy. I now have a modest under-volt on both CPU and GPU to reduce power and temperature, and can use Ultra settings with a few modifications.
If you are sure about your hardware and BIOS, Windows, NVCP settings, then in the sim itself, there are a few things worth looking at.
A few steps that quite a few people with similar hardware use for set up:
BIOS
Windows
NVIDIA Control Panel
NVIDIA App
MSFS
Doing the above gives me almost perfect 64 FPS - which is smooth as silk, and can be variable between 25 (lower limit of my Samsung TV) and 120 (the refresh rate) with Ultra settings and TLOD maxed out to 400…
Except, there are still things in MSFS that cause performance to tank, like Live or AI Traffic, using the EFB in certain planes / scenarios, certain addons, etc.
Final note - with MSFS, any frame rate over 60 becomes visually less important than “Frame Time” … you want the GPU and CPU to be putting out frames at a consistent rate, to avoid those sutters. So above 60, it’s the CPU and GPU latency (in MS) that starts to matter more. Your screen shot shows Main Thread 28 ms in yellow, which is getting high, better down around 20, anything lower than 20 is great.
Have a look at this video, he nailed it. At least it worked for me. (9900X3D)
I know you’re still pretty new to PC, Windows and peripheral devices, so let me give you a quick tip.
The Balanced power Plan can sometimes cause issues - it’s not recommended for some peripheral devices, and it can also affect performance and cause minor stuttering.
Not entirely true - leaving everything else at default besides PBO might work, but it’s not optimal. There are plenty of BIOS settings worth adjusting.
You forgot to mention that it works fine for you.
This is a common cause of stuttering and CTD.
Not all motherboards have it enabled by default. Usually, MSI boards have it on by default but ASUS boards typically don’t.
First of all, the NVIDIA app is garbage. Secondly, DLSS is something you might recommend for VR if someone’s hardware is too weak, but not necessarily for something like my RTX 4090.
FG is often a cause of stuttering and screen tearing. It also adds fake frames that a trained eye can easily notice. This can be really annoying for some people.
These are just a few tips - not enough time and space to cover everything.
My point was, if an issue can’t be solved, to try starting with absolute stock settings in BIOS, Windows, and MSFS. And only change one thing at a time when testing, to understand what each setting does and its effect. What I posted is what worked for me.
Thank you very much for your input! 
No, I didn’t take the screenshot on a second monitor.
Now I started MSFS in windowed mode and opened Ryzen Master as a window next to it. Everything switches as it should to the 3D V-Cache cores, and the second CCD powers down. As soon as I switch to the Ryzen Master window, everything switches back and the distribution looks like in the screenshot I posted earlier. Things can be so simple once you know how they work.
Yep - same thing if you had a second monitor with Ryzen Master running on it. The sim will switch back and forth on the CCD’s depending upon what you click on and you will notice slight micro-stutters when the sim moves over to the other CCD. This is normal behavior.
Glad I could help! 
How is this ‘normal’ behavior? Not being snarky - I genuinely don’t understand.
Shouldn’t the sim use CCD0, and other apps CCD1? Isn’t that what scheduling is supposed to do?
Why would the the sim’s core assignments change when focus switches to another app?
Makes no sense to me.
Not sure why however this behavior has been there since day 1. Maybe consistent behavior would be a better word to describe it? 
Hi guys,
Has any of you tried SU4 Beta and it’s improved management of core use?
I’m in the same situation than OP with nearly identical gear (except I’m in 4K).
At the moment I’m seing a constant MainThread limit (I can run at 200% resolution and pretty much for it to still be the case)
Yesterday I tried activating Gaming Adaptive CCD Parker in BIOS which yield good results in MSFS (mainthread render in around 15ms) but resulted in other games being unplayable (it could be my board ASU X870E Crosshair Hero).
I realized there was a BIOS update to 1715 but haven’t tried reactivating CCD Parker yer.
Tried CPU affinity in Process Lass but I don’t seem to get the same results.
Currently timings aren’t as bad as OP but I’m getting 24-35ms on ground at LFPG with stutters when the GPU is rendering in 10-15ms… (it gives me around 60-70 FPS with TAA and FGx2)
In cruise it gets better timings 19-24ms (and surprisingly it seems better when I’m “focused” on a secondary monitor) but here again the GPU is rendering in 8-9ms (PMDG 777 in cruise over the Atlantic that means around 95-100 FPS on FGx2 (45-50 native) + TAA)
Really hopeful seeing the reports of SU4 but would take any help till then!
What’s your normal mainthread and overall rendering time?
Yes - definitely improved core usage and efficiency is better in SU4 from what I can see.
I’m also in 4k with a 9950x3d but with a 7900xtx however I’m not having any issues.
I’m not always mainthread limited running FSR3 in quality mode. I think anyone running 4k 200% resolution is going to be mainthread limited most of the time 
.
I tried Process Lasso and it did not work out well. To get my PC back working I had to deinstall PL then deinstall my chipset drivers and reinstall them. I therefore would not recommend PL.
I run stock gamebar to control my 3d vcache cores along with the ultimate power plan. Games still run on CCD0 but allow the CCD1 cores to also be used (and the sim will use them). The balanced power plan will basically run everything on CCD0.
For the most part, I’ve focused on undervolting my CPU/GPU and OC’ing my CPU/GPU and memory and not trying to control how my cores are scheduled.
I just happened to have a screenshot of the performance I’m getting with SU4 over New York City - see below. This is SU4 v1.6.11.0 and unfortunately I’m getting 5-10 less fps with the current v1.6.13.0 but that’s how betas go. Click on my gamer pic for my PC details - DM me if you want addditional sim settings aside from what you can ascertain from the fps window.
Thanks, appreciate your answer.
At the moment, to me it seems that the CPPC > Driver setting doesn’t park the correct CCD (CCD1 instead of CCD0).
Through PL, I have managed to force MSFS to CCD0 and the result is night and day (with timings around 8-12ms and a framerate around 120FPS constant in 4K Ultra (with FGx2 and a limiter at 60FPS).
The problem I am having is that over time the game starts to stutter and then freezes (initially 1sec then 5sec, then 20sec etc..) until it becomes unplayable.
My current suspision is that there is something wrong in the way the X3D V Cache is handled by my system (it loads up but never “empties”).
I saw that the am3dvcachesvc is there but it has a stopped status. Even if I manage to start it, it goes back automatically to stop.
I have asked for support from AMD and ASUS (sounds like the X870E Hero might be the source of the problem).
Will keep in touch!
(200% to 8K isn’t something I used but it was just to see how far I was bottlenecked by the CPU Mainthread rather than an actual setting ^^)
As I mentioned above, PL did a number on my PC. Aside from deinstalling PL, I had to use Revo Uninstaller (free version) to totally remove my chipset drivers so I could get to a clean reinstall of the chipset drivers. The gamebar and its supporting services works as it should now.
You might also want to use the Xbox app, click on your gamer pic and then select support. There is a button there that will verify gaming services is working properly.
Hi there,
Not sure if this concerns you, but I had exactly this behaviour when I installed the Windows 11 24H2 preview. (KB5065789). After a Windows repair install all was back to normal
i see KB5065789 in windows update waiting for me to download & install
now i’m afraid to click it 
Yeah, that’s what I did. Who knows, they might have changed it in the meantime, not worth the risk to me.
