@TomT478, I see you're confident enough to open your case. Have you checked if your cooler is OK (i.e, fans spin without any abnormal noise and there's no dust accumulation) and the thermal paste is OK? That's something that can also explain sudden performance losses.

I'm actually going to do that. I agree with you, Ive looked at some of the threads in other places about the later versions of FS, and most people are not that satisfied with them and like you either go back to FSX (not steam,it also has its problems) or P3D. So far those are the two sims that most people like. I've never tried P3D, but most people seem to be satisfied with it as well.  I've got the skills to repair the old 6800, so I'm going to purchase the parts for it and slap that thing back in here and see what results I get from it. I've done probably more than anyone else has done to try and improve my performance on here, with no luck. It's working OK for the time being, still a lot of stutters and FPS drops though. I am just convinced now that it isn't the computer itself, but the GPU just not being compatible with the Intel CPU. If the 6800 does perform better, then I will see about just purchasing an upgraded AMD GPU instead of Nvidia. AMD is still kinda pricey, but not as much as Nvidia. I kind of like AMD better anyway, I only switched to Nvidia because that is what everyone else was using and was suggested by many people on other sites. But doing the research, I found that Nvidia just doesn't fair well with Intel, most people using Nvidia have AMD CPUs and not Intel. I think Intel is geared more toward the business end and not gaming,where AMD is putting their money where it counts, there are more people using home pcs for gaming than for business, and that is backed up by statistics, look it up, I did. Intel needs to jump on the bandwagon for gamers, they have good CPUs but compatibility is a big issue with them.

Also, I did check out all the fans, they are running as expected, they were a little dusty, cleaned all of that off. I replaced the thermal paste both on my CPU and my GPU. I took out all the RAM sticks and cleaned the contacts with alcohol, sprayed dust cleaner into the sockets, replaced a couple of mismatched RAMs, they all are the same speed now. I did a thorough overhaul of the system top to bottom, still I got maybe a 5% improvement, but not that noticeable. I still feel it has something to do with the GPU not being compatible. I'll know when the parts come in for my old 6800 AMD GPU. Oh, and I did have a problem at one time with overheating, that has been solved now. I can't think of anything else to do. I know one thing, I wish I could revert back to Win10 without having to do a complete format and re-load of everything. It's been too long so I can no longer revert back. Win10 ran so much better than Win11. I doubt MS will ever get it to run like Win10 did. The two best OS have been WIN7 and WIN10 so far. I'm actually starting to hate Win11.

This is a little off topic, but I just want to ask a quick question, are there any other developement sites for FSX that I may be able to get some help on other than FSDeveloper. They are ok, but the people there are more or less professionals and do this for a living, I need a site I can get help from that is more aimed at the novice developers.

I just did something that surprised me completely. I uninstalled the MS XBOX app from the system, it gets installed when you install Win11. After I did that and re-booted, my FPS shot up to 37FPS ,still has the FPS jumping all over the place, but it now stays around 2 for the lowest. GEt this though, the XBOX app has NEVER been used and doesn't run in the background, however it did clear up a good chunk of drive space. Could it possibly be that I need a larger SSD for my main drive? I have to install FSX onto the main C drive because all other drives are External and the two other drives in the computer are too full for FSX. FSX won't let me install to a external drive. If I need a larger C drive, that's no problem since SSDs are getting much more affordable now. I could upgrade to a 1TB.

This isn't a development site but you can download the Software Development Kit here:

https://flyawaysimulation.com/downloads/files/2799/microsoft-flight-simulator-x-sdk-sp2/

You'll also find it on the FSX Acceleration disk, if you have it. It's a must have if you plan on tinkering with the FSX configuration files. It's all and only what all those developers had to begin with.

I'm glad you seem to be getting better frame rates. Win 11 is copping a lot of criticism these days. I haven't had any trouble with it but there have been a lot of negative comments I've read.

At first I had no problem with Win11, it was only after about 6 months that problems started to appear. I have the developement kit and I've done a bit developemnet to the sim already. I was just wondering if their were other developement sites out there.

Have you ever had a situation where you have an area in an airport that for some odd reason FSX won't let you add any Land Class or even any Flattens to the area. Well I have one, the airport I'm using is a custom one that I made, and until a couple of days ago it was working fine. But now when I use ADE to add a Land Class such as a forest, it won't show up in the sim. It only shows flat and empty space there, it won't even show the default land which I know by looking at the Google Earth view has mountains in that area. They don't even show up without any flattens or anything there. Is there like some setting or something in the .cfg file that I may have inadvertantly changed while trying to fix the FPS problem. Also, what would cause my FPS to jump around so much? It has gone so far as 38FPS (which proves my rig can handle higher Frame Rates) but keeps jumping all over the place, sometimes dropping to as low as 9FPS then jumps back up to the 20s and somethimes 30s. Is there something in the .cfg that controls FPS and/or displaying of visuals and scenery? I did have a PhotoReal Scenery in that area at one time, but I deleted it completlly, it was messing with Frame Rates. But it acts like it's still there. I've looked all over my scenery folders to make sure I removed all of those files. I'm almost convinced it has something to do with my .cfg. I am first going to try deleting the .cfg and let FSX create a new one to see what happens. (Of course I'll backup my old one)

There's a setting in the fsx.cfg file that can take a small load off the main thread of your CPU. FSX is heavily dependent on the first core of your CPU, and was built in the very early days of multi core and virtual processor functionality, but in SP2 they implemented multi core support. If you add a section to your fsx.cfg file your CPU will offload scenery (and a couple of other things I can't remember) to a number of other threads you can specify with this setting:

[JOBSCHEDULER]
SetThreadAffinityMask=1
AffinityMask=n

Where n is a decimal number the binary form of which depicts the cores and virtual processors you want FSX to use. You can set all of them with 2^number of threads - 1

So if you have an 8 core, 16 multithread CPU you could set this to 2^16 - 1

Gossip says that you should leave one or two threads for other work such as some Windows functionality, but these extra threads won't be working very hard, so will have plenty of clock time to do these other things. Check out your Task Manager to gauge how much work they are doing.

You'll find your fsx.cfg in Users/your name/AppData/Roaming/Microsoft/FSX/

Please take a look to NickN's FSX bible:

https://www.simforums.com/forums/the-fsx-computer-system-the-bible-by-nickn_topic46211.html

The guide is now 12 years old. The hardware selection is outdated (obviously), but the tuning principles are still the same. It's possible you'll need to use Edge in Internet Explorer mode to see all images.

Ok, so I have a Quad Core CPU with Hyperthreading turned on, from what I understand that makes the computer act as if I have 8 cores, and 8 cores is what shows up when I run my CPUID information. So what number would I set the AffinityMask to?

Also, does FSX constantly read the HD that I have some scenery installed on? And is it constantly read/write to the SSD that I have FSX installed on? Could the fact that some of my custom scenery is installed onto an external HDD be causing my FPS to constantly Jump Arround?

With 8 multithreads your affinity mask will be 2^8 - 1 = 255

If you look at your Task Manager on the Performance tab while running FSX you'll see that the sim is updating the number of other threads about once a minute which isn't much.

So the other threads aren't working much at all, but it does take a small load off the main thread, and I think it's safe to assume that your scenery is updated at about this rate.

You could compare the timing of these spikes in activity with the incidence of frame rate jitters.

9 hours ago, TomT478 said:

Ok, so I have a Quad Core CPU with Hyperthreading turned on, from what I understand that makes the computer act as if I have 8 cores, and 8 cores is what shows up when I run my CPUID information. So what number would I set the AffinityMask to?

Can you disable HT in the BIOS? HT will make the computer think it has 8 cores. But, within each pair of cores, these will take turns to work. This means that, for a pair of cores, they will never work at the same time. NickN explained this in the link I gave you. 

Anyway, if you can get by disabling HT in BIOS, you won't need any affinity mask in FSX at all.

I will go in and dissable HT and see what happens. Will doing that affect the computer's performance on other things much? 

It depends on your usage. Since I have an 8-core CPU and 95% of my usage is for flight sims (anything between FS9 and MSFS2024, FSX included), and I don't do any video editing (or something else that may get better performance with HT), I can confidently say that I won't miss HT. But YMMV.

I'll just give it a try and see what happens.