Parallel42 SimFX Released

Here is another example of the problem with SimFX on dirt runways. This screenshot shows the dust produced by ground effect just before touchdown on a dirt runway. At this point the aircraft had not touched the ground at all since taking off from the airport in the distance. Default MSFS looks pretty impressive, SimFX gives nothing at all even with settings at maximum. Note that MSFS has exactly matched the dust to the colour of the runway surface and differs in colour from my 1st post with the DC6.

It seems a shame that SimFX has turned off stuff that default MSFS actually gets right.

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I hope you’ve reported this over on the //42 Discord…

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I reported the problems through their support system and this is their response.

I would have thought that “desaturated and brightened version of the ground texture” would have at least carry a touch of the ground colour, but it does not.

They didn’t respond about the missing touchdown effects shown in my 2nd picture.

There is a lot of good stuff in SimFX, but disabling default effects that actually work is not the way to go, in my opinion.


Anybody know if the performance issues with contrails has been sorted by the developers now?

Hopefully this is something they can address with an update.

No, they aren’t fixed. But even without contrails this addon has a big impact on fps and introduces stutters. I don’t think the developer has the secret sauce to really do something about that. So I wouldn’t buy it unless you really want it and you’re spending most of your flight in external camera or if you’re a content creator and like to do creative flight videos.

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Thanks :slightly_smiling_face:

This is what I expected with the thread becoming pretty quiet but I didn’t know for sure.

The product is an interesting one but given the fps issues with some of its features and also given that I sim inside the cockpit and not in an external view I will give this a miss and see what the new sim brings in 4 months :+1:

<><>TL:DR summary: the Dev Mode FPS counter will tell you if SimFX - or any addon - is going to harm your frame rates.<><>

This is a more general point, and not just regarding SimFX… It’s not really fair to say [Addon X] causes frame rate issues and stutters as an absolute factual statement, because MSFS is the ultimate “your mileage may vary” software. Every system is running at different levels of capacity/overhead, and therefore a given addon will impact each system differently.

HOWEVER… there is a relatively easy way to determine if SimFX (or any addon whatsoever) will cause a noticible impact to your frame rate/sim experience. It requires using the dev mode to bring up the FPS display, which has both the CPU and GPU latency numbers (and the bar graph for overall FPS throughput). No techincal knowledge needed; you’re just looking at numbers and colors.

The top section is the GPU data. This tells you how your GPU is handling the simulator load. This is mainly a function of what resolution you’re rendering at, whether you’re using under/oversampling, and what antialiasing method you’re using. Most current processors should have no issues running at 1080 or 1440 with many (but perhaps not all) bells and whistles active; to get good 4k performance at high settings you may need a newer card/chip.

Buried down at the bottom of the list is the CPU data, which for most people is probably the most important thing to watch. It’s much easier to wind up CPU-limited than GPU-limited with this sim, especially with the proliferation of 8k textures. Because that’s essentially 90% of what drives this number: texture quality (LOD) and size. The number of SimObjects active impacts this as well. (The other 10% is more or less what WASM functions are active, and the general computer-stuff that processors do.)

Right below the FPS/GPU box at the top is a box that tells you what the current limiting factor of the sim engine is - the GPU or the CPU. This is what will guide you as to which addons will impact your experience and which probably won’t.

To use my setup as an example (as I can’t reall use anything else :slight_smile: ), I have a gaming laptop with a i9 12900H processor (24mb cache, 32GB RAM) and an RTX 3080 Ti laptop GPU (16GB GDDR6). This particular laptop has a 2560x1600 monitor (which is ultrawidescreen 1440p, I believe) that can run at up to 200khz. A pretty darn good rig for a laptop that’s over a year old, I think. Could be better, of course…

Anyhow, the Nvidia software tells me that I can run at ultra settings with high LODs with this chip, so that’s how the graphics set up in the sim. However, the Nvidia software doesn’t consider your CPU (because it really can’t), which is also a major factor for MSFS. With ultra settings, I am HEAVILY CPU limited, all the time. Why? Because the CPU can’t push the large textures needed for high LOD, high resolution display to the GPU fast enough. The GPU is clocking along with no trouble whatsoever - there’s lots of overhead available on the GPU side. The CPU box and the limits box are hard red almost constantly. I was getting poor frame rates - like, 15 fps without AI traffic at 3rd party airports – and lots of stutter on camera pans, etc. Also, the system was highly unstable and crashed almost every time I flew. It stank and was no fun.

What I came to learn, thanks to various great minds on the internets (all of whom I thank), is that the key to optimizing the sim is to play around with your graphics settings until both CPU and GPU are right at the edge of going into the red. Believe it or not, this is easier than you’d think. The best way to do it is to set up at an airport that has a good level of detail (so a 3rd party or Asobo handcrafted one), with a plane that has a good level of detail (I used the FSR Mailbu - er, I mean, the FSR500) with dev mode on and the FPS display active, and start playing around with your graphics settings until you balance things out. If you’re redlining CPU, you need to reduce the quality and LOD of your textures. If it’s CPU redlining, reduce your rendering quality however you choose. Another factor for CPU load is how many addons you’re adding via the community folder. The more of them there are, the more textures are being loaded and the heavier the CPU load will be. (I ran… um… a lot of addons.) And some addons put more strain on the CPU than others: the Drzweicki airports are especially hard on the CPU, and FSLTL with its heap of non-avoidable 8k textures is also a hard one.

For me, I wound up oversampling up to 120% or so - since I had ample GPU overhead to accomodate it – and lowering the textures down a few notches. This balanced out the load better between the CPU/GPU without a huge drop in image quality. (There was a drop, mind you, especially when zooming in close on cockpit textures, but it’s acceptable enough, and better than 7fps…) I got FPS in the 20-30 range, which drops when you add AI traffic, but only by 5fps or so. Much better, and fewer crashes. (Note that I also drastically reduced the number of addons loading in.)

With my settings as noted, SimFX had a minor impact on frame rate - maybe 1-2 fps - and did not induce stuttering. There was still enough overhead on CPU to accomodate the additional textures, and my GPU had a good deal of room to work with, so the impact was minimal. But again - that’s specific to my setup Someone else might add SimFX and see things drop dramatically, because they were already at the GPU or CPU limit and adding it overtaxes their system. Your mileage may vary.

This is the ONLY thing remotely close to a debugging tool that Asobo has given us, and it’s a good idea to use it as far as you can to maximize your MSFS experience. Hopefully MS24 will be a new ballgame with fewer problems. (Yeah… I’ll buy that for a dollar…)


While looking at the various sections of the MSFS FPS tool can tell you that what parts of the system are resulting in stutters, it does little for pinpointing the cause.

The only sure fire way to see if SimFX is causing stutters is to run the same flight scenario where you get stutters first with SimFX in your community folder and then again without SimFX in your community folder. Initially your community folder should contain all its usual content, with only SimFX being the difference between the 2 flights.

If the stutters only occur with SimFX in your community folder then this means SimFX is at least part of the cause. You then need to confirm is SimFX is the sole cause or only part of the case. So you would then need to run the same flights again with SimFX as the sole occupant of your community folder, and with a totally empty community folder.

If you get the same stutters as the 1st set of flights then SimFX is your cause.

However, if you only get reduced stutters, then something else in your community folder is adding to the problem.

Lastly if you get no stutters, then SimFX is not the cause.

I personally hadn’t noticed any extra stutters with SimFX over what MSFS occasionally dishes up. A clean boot seems to give me the best result in MSFS.

P42 has indicated they don’t see this as a problem, so it is unlikely they will do any fix.