The questions:
- has anybody tried it yet ?  

 YES. It does not work as well as it is said to but does better on slower systems because they will usually show poorer quality graphics in FSX and the user will never know what they are missing anyway.

- are the frames really improved ?  

It will but do not expect a huge jump, just smoother and you should not run more than 24 locked. I use to try and run my frame lock higher thinking it would be better and I have recently learned a very huge lesson about that and will not be doing that anymore. With it locked lower the scenery is much, much crisper and it flys smooth and without annoying consistent stutters.

- is it only the trees, or is it something similar for the city buildings ?

From what I read there is no benefit to changing the building autogen files


- is the visual impact as minor as described in the readme ?

Visual impact for what... the texture fixes or the tree autogen?  If you mean all the texture fixes, I totally disagree. It probably won’t show as bad on slow hardware but it looked terrible on my system. I will never do those texture fixes again. The patch that is coming out will probably force those who did such fixes to completely reinstall.

If you mean the autogen tree change, I only notice the difference in lack of variety of trees when I am very very low to the ground and only because I ran FSX without the fix in rual areas so I know what it will display, Otherwise I would never know the difference.



I can only tell you what I know from using the texture fixes. At one time I did them all. FSX did not look very good and had problems running smooth  although the frame rate was up as compared to without texture changes. What I found out after I had done all that is those texture fixes on my hardware cause the sim to run and look worse that before.

I asked one of the local experts here for some help and he had me reinstall FSX but only reduce the building textures 50% and install the autogen tree fix that you are asking about. He also said that even those fixes were unnecessary if the video card was a 78-7900 series or better and had 512mb memory. Afterwards he sent me a list of configuration tweaks and slider settings which in combination with the Windows tweaking he posted here at Simviation, and BIOS settings he helped me set up, along with having me purchase 2 gigs of memory has made FSX come to life and fly like I never thought it would.

I am running a 7800GS 256mb PCIe on AMD4000+ and 2gb of memory.

He did say that slower systems can benefit from the texture fixes but only because they will not display FSX as well anyway and the user would not be missing anything by doing it. All it will do is help increase the resources so more visuals can be seen but the quality of them would be significantly degraded for better hardware which is what I discovered.

The autogen tree fix will only help in areas where a large amount of trees are rendered. I was also told it was important to restrict the amount of autogen for both buildings and tress by using the configuration file line edits. For me, this is what works with the autogen slider set to DENSE (3) and the radius set to high or 4.5:

TERRAIN_MAX_AUTOGEN_TREES_PER_CELL=3500
TERRAIN_MAX_AUTOGEN_BUILDINGS_PER_CELL=1000

I was told if I see stutters to reduce them to this:
TERRAIN_MAX_AUTOGEN_TREES_PER_CELL=1500
TERRAIN_MAX_AUTOGEN_BUILDINGS_PER_CELL=700

But so far the stutters I am getting are not that bad and I would rather have the stunning visual scenery over a few small stutters here and there.


And he had me trim the fiber engine back a tad from .33 to .25

FIBER_FRAME_TIME_FRACTION=0.25

and disable the default flight preload:

[Main]
DisablePreload=1

With those edits and a few others he sent me, I am lockled at 18fps in city areas and increase it to 22 once out of a major city radius. Both run exceptionaly well and the scenery is always sharp and clear in the distance.

For pan I was given this:

[BufferPools]
PoolSize=2500000


It fixed my cockpit and spot pan stutters

Also, before I had help I was running this:

TEXTURE_BANDWIDTH_MULT=400

Which I was told is way to high for FSX and is different than in FS9 because of the rendering engine changes. I reduced it to this:

TEXTURE_BANDWIDTH_MULT=80

And many scenery stutters went away.

I was told the slower video cards will probably allow better flight with the texture fixes. The sim will naturally blur them a bit because of the slower system and things like reduced cloud textures will look better than if one is running a faster card. The reduced cloud textures made my clouds look 'blocky' and not very realistic looking.  What I did not like about the reduced ground textures was the quality of them when I looked down. Instead of being sharp and being able to see very clearly the streets, sidewalks and house lots, everything had a 'muddy' look. 

I do not understand completely why but I was getting scenery stutters with them too.

I guess with a slower system it is a trade-off. With the reduced textures you get the flight dynamics back in all their glory. I have seen people post they notice no difference between FS9 and FSX for flight dynamics. I found before I had help setting things up FSX was no where near as responsive for correct flight dynamics. I uninstalled FS9 completely because it does not fly anything like FSX when it is set up right. For me the flight dynamics are a bit more important than scenery.

The maximum value is 5000000. I read up on it and the person from the FSX development team that originally posted bufferpools also stated very clearly 2500000 would provide the best balance between the resources and the tweak. He said any higher and you stand to significantly loose elsewhere but that 5000000 was the maximum value it would accept.

Texture bandwidth multiplier is max at 400. 400 is the max in both FS9 and FSX. That has been posted by both FS9 and FSX developers. If the value (or any value) of a line in the config file is not present or is not within the specified program range set by the developers when the sim is booted, the value will default. The default values when such things occur are unknown for many of the settings.

According to the information I read some time ago on these forums posted by NickN about tweaking the FS9.cfg file for texture bandwidth, it would be quite impossible for a value of 600 to work unless the person is running a 1gig video card.

The number multiplies a hidden value called the TextureMaxLoad. By default that is 3. The TextureMaxLoad is the number of 256x256 (in FS9) textures to be loading in KB to the system. The TEXTURE_BANDWIDTH_MULT does exactly that, it multiplies that number. So that would mean Mango is loading 600x3 (1024x1024 in KB) assuming he has not installed a texture reduction tweak and even if he has and is running 256x256 textures, it is mathematically impossible for a video card memory of less than 1gb to work a value of 600 for the multiplier

The value has simply defaulted to a number that his system likes and he thinks 600 is working.

NickN told me the TextureMaxLoad= value can be edited into the FS9.cfg file however he said that setting is not available in FSX because the rendering engine is different. I used NickN's FS9.cfg file tweaks and that sim never looked or flew better. The values he posted for FS9 in the area we are discussing were:

TEXTURE_BANDWIDTH_MULT=160 (and reduce to 100-120 if stutters occur)
TextureMaxLoad=8 (reduce to 6 on slower cards)

It was stated that 128mb cards may not be able to handle that setting and that 256mb cards were recommended for its use. If a 128 card is used, a value of 6 / 80 may work.

160x8=1280
400x3=1200 (default TextureMaxLoad)

That produces almost the same total value, however the difference is the fiber engine is directed to load the amount in KB of 8 256x256 textures (instead of 3 256x256 textures) and reserve the resources for the the bandwidth. That forces the ground textures to take priority and the fiber engine will then sharpen them before it does anything else. When correctly tuned with the other settings in the config file the difference in FS9 is night and day when it comes to stutters and scenery loads.

FSX uses FIBER_FRAME_TIME_FRACTION and the TextureMaxLoad is no longer a variable.


It was explained to me that slower video cards may like a higher multiplier in FSX simply because the user is forced to reduce the sliders in order to get the sim to fly smooth. In doing so, the multiplier can be raised and a higher value can have a positive affect. However, on a system that has the sliders tweaked up and is running under stresses, that value is best reduced. The amount is based on the system and what is being rendered. Considering the textures are 1024x1024, a multiplier of 400 on a system that is trying to render autogen and other models, is quite ridiculous unless the user has a superior video adapter. A setting of 60-120 would be more reasonable, 80 being the middle ground and is what works best on my setup.  

Ok I have a problem with your explanations.
You were talking about TextureMaxLoad.
I don't have that yet in my FSX.cfg. The only thing I have is Texture_Max_Load that is set to 1024, and which seems to determine the maximum resolution of the loaded texture. I set it to 8 and the texture of the aircraft preview was just a big blur I guess it loaded the texture in 8x8 pixels format 

So, is your parameter name correct ? And if yes, in which section of the FSX.cfg should I insert it ?

Your explanations are clear and I could understand them well, thanks again for that 
I have tried with the settings you recommended before your last reply, since I could figure out were to place that hidden parameter.

The results are just great ! Now, flying the Jenny over Innsbruck, I get a stable FPS average (most of the times locked at 20, then when panning slows down temporary to 15), and the disk accesses are greatly reduced, involving less stutters while panning around. 

That's cool, this sim is performing better and better. Still too heavy on the ressources to fully enjoy the liners over big cities are any other fast jets (my scenery loading is too slow for that, I would quickly get blurries), but for any propeeler aircrafts, the experience is great. And for the gliding, the sim has just become perfect ! 

Too bad I cannot spot those birds

Interesting...
My settings regarding the scenery are almost all maxed out when I fly out of big cities, but my GA traffic is set quite low... I will try to modify that. Once again, thanks for the info !