The balance between Ai percentages and frame rates has interested me for a while. As you increase or reduce the percentage of Ai aircraft the actual number of aircraft displayed does not change in proportion. Here are some observations taken at EGLL using Gary Summon's Heathrow Pro v2 and Ultimate Traffic with my aircraft slewed at 750ft 1/2 mile from 27R...A = Ai percentageB = Frame rateC = Ai aircraft displayed.A B C100 11.7 97 90 16.3 71 80 20.3 41 70 20.4 41 60 20.5 41 50 20.6 41 40 21.0 41 30 20.5 41 20 23.8 23 10 24.8 23 0 36.2 0 Looking at these there are only roughly five settings - 100, 90, 30-80, 10-20 and 0. There will be some differences between 80-90 and 90-100 but nothing between 30-80 so it makes no difference whether you set Ai at 30 or 80 percent. Of course these numbers are only at one airport but as EGLL is one of the busier international airports it seems a reasonable choice. The best compromise seems to be 90% which increases the frame rate by 50% but only drops the Ai percentage by 26%. Less aircraft to see but shorter queues and better landings with the higher frame rates. BTW, these numbers are on my P4 3.0, Radeon 9800 Pro 128Mb, Omega Radeon drivers v2.6.12 and with clear skies.Cheers,

Thanks for that. Very interesting.By the way. EGLL is not only ONE of the busiest international airports. It is THE busiest! :-) ;-)

Hi Victor,<>Ah but that depends on what you use as a measure - Movements or passenger numbers will produce different league tables.Anyway, I know your point was made and received in a light-hearted manner and that you appreciated the numbers but I hope this thread doesn't drift off topic ;-)Cheers,

Excellent stuff Ray., as you say looks like 90% Ai is the optimal settingCheersDan

That is true--it's been a long while since I've played with adding AI traffic, but basically the percentage is a figure above which your AI won't be displayed, not a measurement or filter of actual AI in the air. -JohnEdit: I should note I am making reference to the process of adding an AI track. I did this with Lagos Ultralight collection in FS2002 so I would have a string of their Ultralights in the sky regardless of the AI pct.

Hello Ray,Very interesting figures. I wonder about them, though. As John points out, the traffic settings may signify something different altogether.AI flights all receive a "Traffic Percent" setting that determines whether that AI flight will be displayed, depending on the user's FS setting. Flight Simulator does not seem to have any other criterium for displaying a flight or not.So, before coming to any conclusions as to the number of aircraft in the air, it may be interesting to take a look at the traffic file and see exactly what the "Traffic Percent" is for all those flights.That is, if AI flights are all set to display at either 10, 30, 90, or 100%, then your results would make a lot of sense.But, if the "Traffic Percent" setting for AI flights were to be uniformly distributed from 10 - 100% for all flights, then your results might be completely different.Best regards.Luis

Hi Luis / John,You're quite right in that Ai aircraft are displayed only if the flight they are associated with has a percentage rating equal to or lower than what you have set in your Ai options.I suspect that with a package like Ultimate Traffic flights will be grouped towards the higher percentage settings - hence the dramatic reduction in flights as the percentage is reduced.I have no way of interrogating a decompiled traffic.bgl but it would be interesting to see how the flights are grouped. I very much doubt the flights are uniformly spread. I suspect they are bunched which would backup my initial findings.In the meantime I'll check a couple of other airports. In case you were wondering how I knew how many aircraft were present I used the map in FS Flight Keeper which displays and counts Ai aircraft.Cheers,

Hi Ray,Thanks for your work in providing your findings on AI impact to fps. I purchased Heathpro 2 this weekend and have been tweaking my P4 2.4ghz, 768mb rdram, 5900XT for best frame rates. Using your info as a guide, I tried to mirrow your settings for distance in spot view. Scenery complexity@very dense, global@massive. Used Eaglesoft

Well, what one could do is set up an AI flightplan of 100 identical flights but change their percentages in 1% increments. Then start decreasing you AI slider by 10% increaments.But then if you do this... you really have too much time on your hands ;)

interesting find, but with all the time and enjoyment I get out of manually setting up my AI, nothing below 100% will do for me.

Hello Ray,It is easy enough to see the contents of traffic files. They can be decompiled using Lee Swordy's TTools (Traffic Tools) - this gives a text file that can be imported into a spreadsheet or a data base for manipulation.Even better, Thomas Molitor's AI Traffic Mover (AITM) will display this file and allow for sorting. Here is the default traffic for Heathrow, sorted by Traffic Percent:http://forums.avsim.net/user_files/119632.jpgA very good distribution of traffic for all Percent settings.And Project AI's files are really outstanding in this sense. There is a good mix of traffic for all Percent settings, from the lowest to the highest.So, we could perhaps say that a good flight plan is not simply one that contains all an airliner's flights. It should also have a good variety of flights at all settings.Best regards.Luis

Hi Luis,I notice you use Project Ai flights which clearly spread the flight load far more evenly than Ultimate Traffic. I have decompiled the traffic.bgl in the past and I am familiar with Access so I might feed the data into a database this evening and do some analysis.<>Agreed!Cheers,

Hi Carl,Two points from your message...1. You mentioned having static aircraft at EGLL. You should be able to remove those which will free up parking spaces. They're usually contained in a single BGL. The readme may point you to the relevant one.2. You've limited your frame rate counter to 20. I've been doing this recently with my P4 3.0 but at the weekend I decided to try it sat to unlimited and I'm far happier with the overall performance of FS. Try it, you might be pleasantly surprised. The frame rates will certainly increase with 50% or less Ai aircraft loaded.The analysis I reported at the top of this thread was based on early evening at EGLL. I can't be precise. As you say there are so many variables we could never come up with similar numbers but the topic is useful as it will get people experimenting with Ai traffic levels - one of the biggest performance hits in FS9.Cheers,

Am I right in thinking that this program has a facility to load a set of flight plans and then randomise the AI percentage?This presumably gives a even distribution and therefore much better control over the number of AI aircraft which appear.I've been using MRAI flightplans. Their installer allows you to opt whether to randomise the percentage or not. I randomise the big airlines (how many BA 757's do you want at EGLL?) but not the small ones or more exotic ones, which I assume then complile at 100% AI and therefore appear whatever your traffic settings.That should (I suppose) give a varied mix of AI traffic - although not the complete accuracy MRAI could offer if all the airlines were compiled at 100%

Hi Luis,I've extracted FLIGHTPLANS.TXT from TRAFFIC.BGL and imported it into a database. I've only looked at EGLL so far but the spread of flights does match with my post last night. Here are the details...A = Traffic percentage range for flights.B = Number of flights.A B90-100 5680-89 4270-79 060-69 050-59 040-49 030-39 220-29 3410-19 4< 10 44I wonder why UT developers had such an unblanced set of flights? Maybe it just matches the real world but it does seem odd nevertheless.If I was really keen I would spread the load and recompile but to be honest that's a job for retirement and I still have a few years to go ;-)Cheers,