Does anyone have any knowledge as to whether addons such as scenry etc, decrease the sims performance or does it make little real difference?Paul.

"Does anyone have any knowledge as to whether addons such as scenry etc, decrease the sims performance or does it make little real difference?"Yes, add-ons can decrease performance although some simply make the sim look better. A complex aircraft can impact sim performance, a detailed scenery area, photoreal scenery, and so on--all can impact peformance. Sometimes the performance isn't measured by the framerate counter--it could be simply slower loading textures, or textures that tend to blur. Or it could be "pauses" while the sim loads detailed scenery.Some add-ons are pretty benign and improve the sim's looks while having no adverse impact on performance. Environment add-ons like FE are an example, and quite often users report improved performance. I have USA roads installed on an old P3/800, and I couldn't measure any performance impact. But if I load a "simple" aircraft, such as a flyable low poly AI model, performance in the sim improves markedly--the sim isn't processing polys, a VC etc.... Hope this answers your question!-John

Thanks for your reply, what i meant though was, having lots of addons installed, does this sort of hog the sim to some degree and reduce its performance, if you know what i mean?Paul.

1. Fresh install with marginal to no ai + default cessna and scenery = no impact.2. Install with for example Overland Scenery Kansai with 100% custom ai and for example PMDG QOTS. = YES impact and frames do gown down. (Looks great though) but you'll be flying a slideshowSo to sum it up as to "having lots of addons installed". Some add-ons like planes and scenery, can/and will cause a degration in peformance, whilst using a mesh or landclass won't hurt.Thats what you ment i think, right?

Say for instance i installed 20 add on sceneries and 10 aircraft, 5 lots of mesh, will the sim struggle more even though i am say using one scenery and one aircraft at that particular time.Paul.

No. The performance will be determined by whatever scenery/aircraft/weather combination you are using at the time. All the other unused stuff just sits there and has no impact.Doug

"Say for instance i installed 20 add on sceneries and 10 aircraft, 5 lots of mesh, will the sim struggle more even though i am say using one scenery and one aircraft at that particular time."MSFS loads scenery and mesh based on where you're flying. Unless the scenery isn't written or organized well, even if you loaded up say, Asia, with 100 mesh files and 100 new airports, your flying in North America wouldn't be impacted.The aircraft menu may take longer and longer to load with more aircraft, but once an aircraft's loaded, MSFS doesn't care about the other aircraft in your library.However, if you're lazy about defragging or move files to and fro', you may end up making MSFS work harder to retrieve the data it needs when flying. The biggest performance hit you "could" take is when you load general add-on texture sets or incorrectly install landclass, or load a "broken" AFCAD. If you install universal add-on textures, you should ALWAYS defrag. If you install Landclass, you should NEVER have an empty texture folder present in the same folder structure where you've placed the Landclass. And broken AFCAD files are known to cause issues on the far end of the globe from where they cover.-John

"you should NEVER have an empty texture folder present in the same folder structure where you've placed the Landclass"Does that mean you just have the scenery folder placed in the land class folder or should it have a texture folder with contents included?Paul.

"Does that mean you just have the scenery folder placed in the land class folder or should it have a texture folder with contents included?"You just have the scenery folder placed in the land class folder.-John

"But if I load a "simple" aircraft, such as a flyable low poly AI model, performance in the sim improves markedly--the sim isn't processing polys, a VC etc...."A question about this:Is it possible to remove everything BUT the VC?And, if so, would this make a difference in performance?thxAndrew

"Is it possible to remove everything BUT the VC?"MSFS only processes what it sees in a given window. In the case of an aircraft with a VC, when you are in the VC, MSFS is only rendering that part of the aircraft. The exception is if a designer simply copied the whole aircraft into the model used for the VC. These are pretty rare. The reverse more often happens--when a working VC is part of the exterior model. That slows performance in spot view quite a bit so I avoid it in my models, opting instead for a texture bmp I overlay on the panel.-John

How do we detect broken AFCAD files? thanks.Jason

I don't have any AFCAD files installed myself, but I thought someone wrote a tool that could detect them or at least checked their integrity. Broken AFCAD's usually don't hit performance--they hit stability. Sudden CTD's for no good reason, etc, can be a sign of a broken AFCAD.-John

> If you install Landclass, you should NEVER have an>empty texture folder present in the same folder structure>where you've placed the Landclass. I was told this is a myth, that only an EMPTY texture folder causes a memory leak. For example, Flight Scenery Rhode Island has a landclass file with an associated texture folder, but this landclass file tells the textures where to be placed and does not work if it is in another directory

"I was told this is a myth, that only an EMPTY texture folder causes a memory leak. For example, Flight Scenery Rhode Island has a landclass file with an associated texture folder, but this landclass file tells the textures where to be placed and does not work if it is in another directory"I'm sorry--I meant an empty texture subfolder--it's not a Myth, just a misstatement on my part. However, there's also more than one method of creating a landclass file. Standard landclass, such as that created with my tool, Landclass Assistant, does not tell the textures "where to be placed". But a slight variation of the text file that builds the landclass allows for either photoreal scenery or custom bmps that can be used in place of the standard bitmaps. For those you would need custom textures and of course, a texture subfolder. 99.9 pct of the landclass out there does not fall in this category.-John