I do all my flying in MSFS2020 in VR using a MeganeX Superlight 8K VR headset. Primarily flying the iFly 737 MAX8 online on Vatsim to/from payware airports. Many of them rather complex.

My current rig consists of a 13900K with a 5090 and 64 GB RAM. The performance is OK but I don't have that perfect smoothness I see when flying a less complex aircraft to smaller airports. I suppose that will be hard to achieve with the hardware we have available to us today but if I could at least see a noticeable improvement by rebuilding my rig, I would be willing to give it a try.

On that note, one thought that crossed my mind and especially after seeing how the bottleneck mostly seems to be the main thread is if it could be worth giving a fast AMD CPU a second try. Earlier this year when I still had a 4090 and a Varjo Aero, I did that test but ended up going back to my current system. This after not seeing much of an improvement if any in VR. In 2D mode, I did see an improvement.

What I'm thinking now when I have a 5090 instead of the 4090 I had last time I tried. And in combination with seeing how MSFS2020 is bottle-necked by the main thread, I'm thinking replacing my CPU with a fast AMD maybe is exactly what I need to get the most out of my 5090/my system. Potentially seeing a better improvement than last time, this time with a more powerful GPU. Sadly, I don't recall when I tried last time where the bottleneck was - the CPU or the GPU.

Anyone in here have any experience with a quick AMD CPU together with a 5090? With the MeganeX Superlight 8K or a similar headset?

As for fast AMD CPUs, last time I got the 9800X3D but now we have the 9950X3D. More expensive but if that CPU would help getting the most out of my 5090 and the best possible smoothness, I would be happy to pay that extra money. I see how the 9950X3D comes with 16 cores. Where the 9800X3D comes with 8 cores.

Not sure how much of a difference that makes in MSFS (2020 and 2024). What I do remember though is how I found the 9800X3D to perform considerably worse than my current 13900K for other things than MSFS. Such as multitasking, unzipping files etc. Which I assume was because the lower number of cores.

For that reason alone (since I do like to have a quick system not only when running MSFS), I would be willing to get the 9950X3D over the 9800X3D even when more expensive. As long as it doesn't perform worse than the 9800X3D in MSFS for whatever reason.

Any input or thoughts on this highly appreciated!

From my observations, the 9800 x3d is at least 20% better in performance compared to the 9950 x3d, regardless of the 96 MB L3 cache vs. 128 MB L3 cache, using MSFS 2020/2024. I changed from a 14900 KS to the 9800 X3D and have no regrets. Now, regarding core numbers, it's obvious that tests show different numbers to be taken into consideration. The way I use my PC, I can't tell the difference between unzipping and multitasking, and I also do photo editing without noticing any difference between 14900Ks and 9800 X3D. I think you should conduct further research on this topic to draw your own conclusions. 

 

Thanks for sharing your experience!

Looks like the 9800X3D is the better option but will try to dig around a bit more.

What will be most interesting if I decide to give replacing my 13900K a second go is what difference it will be that I'm now pairing it with a 5090 instead of a 4090.

44 minutes ago, WebMaximus said:

5090 instead of a 4090.

I'm sorry, I forgot to mention, one gentleman replaced the 4090 with a 5090, and the noticeable difference was about $3K, with just maybe +15/20% improvement or so that I could notice in MSFS2020/2024, and still issues related to the CPU optimizations. If you have an RTX 4090, imho it's not justifiable getting an RTX 5090. Currently, even P3D and XP12 are significantly better CPU performers than MSFS. Hopefully, they will fix it.

I agree the 5090 is crazy expensive but in my experience, it's when running at very high resolution you start seeing its pure power vs the 4090.

Reason I replaced my 4090 with a 5090 was exactly that, the very high resolution in the MGX. Where the 5090 even at full native resolution leaves me with being bottle necked by my 13900K.

Didn't get a chance to compare since I sold my 4090 but I don't think I would have seen the same thing with the 4090.

I have  both 9800X3D and 9950X3D, but currently only have the 9950X3D installed in my flight sim computer.

If you operate at 3440 x 1440 and list your current graphics settings (all), add-ons, and specific location and aircraft ... do a circuit and I can do the same and provide you with the log data and video so you can compare.

5 hours ago, SayAgain said:

I have  both 9800X3D and 9950X3D, but currently only have the 9950X3D installed in my flight sim computer.

If you operate at 3440 x 1440 and list your current graphics settings (all), add-ons, and specific location and aircraft ... do a circuit and I can do the same and provide you with the log data and video so you can compare.

Thanks, that's very kind of you.

However, since I do all my flying in VR using the native resolution in the MeganeX Superlight 8K, that is the the only data which is truly of interest to me. I think I already mentioned it above but back when I tried a 9800X3D with my 4090, I quickly discovered how the gain over my 13900K was considerably more in 2D mode over VR.

What would be interesting is if you saw any big difference between the 9800X3D and the 9950X3D in similar scenarios in MSFS. 2020 most interesting to me since I still haven't jumped to 2024 but will do eventually. So also any testing you did between these two CPUs in 2024 would be of interest. 

Today, I did my first flight after replacing my 13900K with the 9950X3D with a new motherboard and 64 GB DDR5 6000MHZ CL32 RAM and must say I’m pleasantly surprised!

Best way to describe it is how I went from like 85-90 % smoothness to like 95+ % in the iFly 737 MAX8. Which was exactly what I was hoping for.

Wasn’t expecting it though after my last visit in AMD land when I certainly didn’t see this improvement.

Further testing required but felt great being surprised in this positive way after the money and effort which went into this. I think this is a keeper 👍

1 hour ago, WebMaximus said:

9950X3D with a new motherboard

Make sure you have the following updated:

• Latest EFI/BIOS AGESA microcode for your motherboard
• Latest AMD Chipset drivers 
• Latest Windows 11 24H2 updates

This increased my performance by about 13% as the CCD/VCache work much more efficiently with Win11 24H2.

Unfortunately many reviews don’t do a re-test once published.

Edited July 23, 2025Jul 23 by SayAgain

12 minutes ago, SayAgain said:

Make sure you have the following updated:

• Latest EFI/BIOS AGESA microcode for your motherboard
• Latest AMD Chipset drivers 
• Latest Windows 11 24H2 updates

Thanks, already on the latest of all these and now I'm just about to try out Process Lasso to see what that might bring to the table.

Im exactly in the same boat  i9-13900, 5090 and 64 GB RAM. CPU fried. Thinking to switch to AMD Ryzen 9 9950X3D. Haven't used AMD for a very long time. Last time I had bad experience with AMD and "hit and miss" performance. Initially I was  considering i9 ultra 285k but review of this chip is rather unflattering.

Must say I'm very happy with my AMD rig!

I'm now on MSFS2024 SU3 but still doing the same type of flying - online on Vatsim in the iFly 737 MAX8 in VR.

Initially struggled to have the same smoothness as in MSFS2020 but then dropped the resolution in SteamVR to match the native resolution of the MGX and switched too TAA instead of DLSS Quality.

Was properly surprised I have the best smoothness I think I ever had using these settings. Surprised since I previously always experienced how TAA isn't as smooth as DLSS.

Do note this is with SU3. Where SU4 is supposed to be WAY better. So I can't wait for SU4 to be released! Considering the awesome smoothness I already have with SU3.

Should also mention I ended up not using Process Lasso. The AMD service for X3D optimisation together with Game mode enabled in Windows already does a great job putting all the heavy lifting on the right CCD (CCD0) with the extra cache 👍

2 hours ago, sd_flyer said:

Thinking to switch to AMD Ryzen 9 9950X3D. Haven't used AMD for a very long time. Last time I had bad experience with AMD and "hit and miss" performance.

AMD is more hit than miss these days.  Companies change over time, some get better, some get worse.  Intel is currently on the worse side ... but I hope Intel recover, competition is good.

Once AMD and Microsoft got a better idea of their partnership, OS specific features for AMD eventually got incorporated.  Also, keeping AMD EFI/BIOS updated is VERY important (both for security and performance and stability).

59 minutes ago, SayAgain said:

AMD is more hit than miss these days.  Companies change over time, some get better, some get worse.  Intel is currently on the worse side ... but I hope Intel recover, competition is good.

Once AMD and Microsoft got a better idea of their partnership, OS specific features for AMD eventually got incorporated.  Also, keeping AMD EFI/BIOS updated is VERY important (both for security and performance and stability).

Thanks. So I’m jumping to AMD for PC flight sim as of right now . Will have to go through borrow reinstalling everything once again !

Funny thing I'm finding my 11600k is only loaded 60% but my 70080xt is at 100%...so could I expect improvement going to a 14600k?