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cargodor

Is there a limit to the number of AI you can have in FS9

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Hi all. Am rapidly enjoying filling up the new Aerosoft LHR scenery with AI. But am getting very frustrated as there seems to be a limit to the number of a/c that are displayed. I have trebble checked that I have installed the aircraft correctly, checked the Traffic tools files are correct. But some aircraft just will not appear. Have tried with several models. Is there a limit or a file one can modify to increase the amount visible.Thanks in advance for any help.Matt

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There is no limit to the amount of AI flightplans you can have in FS9. That was not the case with FS2002. You may have one or both of these conditions. 1.Your traffic is not set to 100%. 2. not enough parking at the selected airport.Bill

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I assume you have the AI% slider to it's maximum.The most active AI aircraft I've seen is a little over 1,200 in the London area.Now, the vast majority of those were not visible - they were active at other airports around.FS2004's BGLComp SDK has a limit of 255 parking spaces per airport, but AFCAD will let you add more.The key though is the amount of parking available. If you don't have parking - you won't see planes.But I want to emphasize this - you must have sufficient parking at Gatwick, Luton, Stansted, London City, Biggin Hill, Farnborough and all other airports within 110 nm of your aircraft - or you will get major performance hits.

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What's the logic behind the statement that too little parking causes a performance hit?As someone who crawls across London at about 2 FPS I need to know!I'd have thought the performance hit comes from the number of aircraft which are visible (or at least being rendered by FS).If you have too little parking, planes land and then disappear - galling if you are on the taxiway or approach at the time, but not a hit on performance.On the other hand, add parking and you are potentially rendering more planes = bigger demands on your PC = performance hit.

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Reggie Fields...... "But I want to emphasize this - you must have sufficient parking at Gatwick, Luton, Stansted, London City, Biggin Hill, Farnborough and all other airports within 110 nm of your aircraft - or you will get major performance hits." What or who's situation are you referring to in this statement? Can you give us an example of why you say this please. What is going to cause the performance hits? Harold

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AI aircraft cause two hits in performance - in the graphics routines and in the CPU routines.For graphics - we are all familiar with the basic equation - the more polygons displayed, the more graphics power it takes to display them.There are also issues with memory and caching all the textures, etc. FS has to cache everything in a 360 direction of your aircraft for many miles to be able to handle the demands of switching views and aircraft movement. This includes caching information about every active AI aircraft texture within about 108nm of your aircraft in case you want to switch AI aircraft views with CTRL+W.Yes, that is a lot of data - too much for any system memory - but it is all still has to be identified and ready to load. Waiting for a scan of all the aircraft.cfg file fltsim.x sections and all texture files takes too long. The data to load the aircraft has to be ready for instant use.If you will use the Traffic ToolBox Explorer and the Traffic Toolbox Map - you will see how many aircraft are active in your area.FS uses a simplified AI control system - but what it does use takes a significant amount of CPU cycles.One thing which FS does is the initilization process of AI aircraft - and retry if there is not a parking spot available.You can watch this hang as FS tries to load AI aircraft at places without sufficient parking. Does your system seem to stop at 78% or 82% or 98% while loading AI traffic before starting a flight?This is the continual retry to park more AI aircraft than you have parking spots available. This attempt to park AI aircraft continues through out the flight sim session - so that same performance hit occurs many times each hour.FS does not go - Oops Stansted has no more parking.It goesRead Easyjet traffic file - park B737 at Stansted - no parking available - retry - retry - retry - retryRead Ryanair traffic file - park B737 at Stanstead - no parking available - retry - retry - retry - retryThen about five minutes later - the whole process repeatsIt also repeats whenever an AI aircraft moves from a parking stand and a parking spot becomes open.Microsoft warns us a couple places in the SDK's that more AI than available parking spots will have a noticable negative impact on performance.Try adding AFCAD's for those other airports to the London area and see if your performance improves.

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Reggie,Thanks for the informative explanation.I always wondered why FS would slow or even hang up somewhere in the 90-98% area.I'll be looking to improve parking and see what happens.KJ

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Hi there Reggie and all other technical FS9 experts,Thanks for your detailed info but in order to be able to attack this performance problem or at least check if the problem exists, I have some further questions, just to be sure.This "no AI parking available - retry - retry-" thing.Can I assume that this process takes place only at the airports from which I wish to depart with my user aircraft, from the moment that I open the flights concerned ? Does this process continue even after I have taken off ?Are AI Parking spots at other airports within a certain radius of my user aircraft, also constantly checked in this way, even at standard airports at which I never arrive or from which I never depart ?I do notice some "stops" during the loadingprocess of AI traffic but these are only fractions of seconds. But if these checks continously take place, even during long flights, then I believe we almost all have a problem. I have per catagory checked very many AFCAD parking spots by now at my departure and arrival (addon) airports but have found none (yet) on which all available parking spots were occupied.Would this mean that I don't have the problem ?Friendly regardsHans

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AI aircraft are active at all airports around your aircraft. This is normally up to 108nm from the user aircraft.At Heathrow this means at least four other major commercial airports and about a dozen other airports.The parking process occurs at ALL airports in your active AI zone.Yes the parking process continues as your fly over the various enroute airports.If you fly on a course which makes New York City within your Active AI Zone - then KJKF, KLGA, KEWR, KHPN, KFRG, KTEB, ...... all will load.It is not uncommon to have a stutter when a very busy AI area becomes active during your flight - because at a certain distance - and airport will 'load'.The way FS scenery works is a grid system - and AI traffic is scenery, moving scenery.Your aircraft is in a grid. Then everything in the eight adjacent grids is loaded or read and cached if it is not visible. Plus depending upon your location - other grids may also be read and prepared for instant loading.AI traffic files consist of grids and time. During time X in grid Y aircraft Z is supposed to be at airport ABCD.If at that time your aircraft is at airport EFGH seventeen miles from ABCD - then that AI aircraft is supposed to be parked at ABCD.Enroute/ flying AI work the same way.This is one reason that FS is the most intensive computer game in the world - because it has to keep an active world operating around us.If FS did not do all this massive caching and calcualtion of things your cannot see --- the stutters would be so massive.FS would have to determine the viewpoint and direction of travel, read all the scenery files, determine which files have objects which need to be active, read the textures, display the objects, calculate any motion.This would have to occur every couple miles of travel when we are in flight.FS works a bit smoother by trying to cache everything 100 nm from your aircraft - again - it has to consider all directions because you might divert or turn back.That way FS can stream in the 'new' objects a bit slowly and build the cache of active material so it will be ready when your display.However, bringing an airport with 150 aircraft on the ground into the active 'world' is a big hit. You will see the same thing when you fly to a very detailed scenery even if no AI are active.

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Hi Reggie,Is this also the reason that AI traffic will "freeze" ( for lack of a better term ) if I open a flight with close to 100% traffic in UT on a busy airport? For example, the other day I started my flight on the tarmac at KATL. The time was 16:30 local. I noticed right away that something wasn't right when no aircraft were moving on the airport. I left the aircraft sitting there until about 17:45 and not one aircraft moved, although there were many flights scheduled to depart. Aircraft that landed disappeared right after touchdown.I moved the time ahead 5 minutes in FS and after reloading all was back to normal, AI moved as soon as the flight opened up. Was this just a case of too much AI for FS to handle?John

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I'm not familiar with that happening.FS2004, like FS2002, loads extra aircraft on the ground - all the AI aircraft which should have departed in the past 15 min. FSX doesn't do that.A five minute change should not force a reload of AI aircraft - normally you need 15 min.But if something about your traffic files causes a hang, I could understand it gets things moving.One of the biggest overloads at airports like KATL is the comm frequencies. With all the aircraft asking for clearance - it's easy for FS to get out of sequence and have aircraft stuck in transition from one mode to another.I suspect your issue is the volume of AI traffic active on that airport. Have you checked with TrafficToolbox Map to see if enroute AI are flying/ moving?

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Thanks for that - most interesting.I deleted a lot of Afcads because I was getting CTD's and as they weren't airports I use regularly, it didn't seem to matter.Maybe I'll try putting them back and see if that reduces the hit I get over London.Mind you, with the amount of AI I have flying over there, I feel as if I'm the duck in a shooting gallery anyway. Especially when FS ATC decides it's a good idea to route me across the business end of Heathrow at 3,000 ft on my way to Biggin Hill........

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Thanks for the reply, next time this happens I'll check on AI flying overhead. The frequency overload for clearance delivery could be what happened since at 16:30 @ KATL there are many flights scheduled to depart at basically the same time. I actually let it sit until about 17:15 before I moved the time ahead 5 min., which may have freed up enough clear radio frequency space.I remember it happening one other time at KIAD, I believe. That time I just went ahead with the flight after a 15 min wait to stabilize the weather and the AI started behaving normally once I contacted the tower and taxied out.John

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Hi Reggie,Unbelievable, the amount of thinking work which those guys at Microsoft must have performed in order to develope FS with all it's extremely complicated (hidden) functions etc. They never stop impressing me, even after more than six years of FS experience on my part.However, as a result of your highly appreciated technical explanations it would seem a logical question in asking how to reduce the 108 Nm active AI radius around user aircraft, a.o. because addon radar/TCAS systems only go as far as 40 Nm max. and, by the sound of it, standard ATC even less. But I assume that that would be almost impossible due to some of the FS9/FSX basics a.o. the world wide grid sizes, all of which would then have to be reduced as well.You speak about a lot of (AI) data from the eight grids around a user aircraft being cached for instant use. Sounds very logical but is this solely done in the systems memory ? If yes, could this mean that 2 Gb can sometimes overflow onto a HD page file, especially in combination with complex addon user aircraft, panels/gauges, sceneries, weather, and ..... many many active AI aircraft within the 108 Nm radius ? Is 2 Gb sufficient ?Well, for the moment it seems that some of us more technically inclined armchair pilots will just have to wait for Intel/AMD to produce even faster processing systems/capacities, especially for those of us with huge amounts of addons etc. and who prefer maxed out sliders without stutters and marginal frame rates. Do you or does anyone else know of any (possibly drastic) Intel/AMD plans in that direction ? Or is processor heat production/energy consumption still the main obstacle.RegardsHans

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The 108 nm of FS2004 is a little over double the distance of the Active AI Zone from FS2002.When MS added real world approaches - they had to increase to about that size to get AI to work with the system. (If MS adds STARS to FS11 - the zone will have to expand exponentially again).It is impossible to change the distance. 108 nm appears to be the upper limit - though near national borders and major airspace boundaries it is shorter.KSAN and SPIM are two airports where the zone only appears to extend 40 nm to the east. Jim Vile had trouble with LOWI because the pattern would push AI aircraft over Germany - and that's not part of the Austria AI zone.Yes, I think it is quite common for things to be pushed out to the page file in FS, textures especially.One of the blogs recently talked about how much FS has to cache and keep ready for display. It's massive.I've got no idea where FS11 is going - but I don't see increases in processor speed.We might all need quad-core processors with dual SLI DX-10.1 graphics cards, a 5,000 watt PSU and the radiator from a Mack truck to cool the thing in two years.

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>But I want to emphasize this - you must have sufficient>parking at Gatwick, Luton, Stansted, London City, Biggin Hill,>Farnborough and all other airports within 110 nm of your>aircraft - or you will get major performance hits. I fly exclusively in and out of London Stansted and have developed a "trick" that prevents my system being bogged down by unwanted AI flying into and out of the other London majors.Only flightplans that contain a flight into or out of Stansted are allocated an AI% of 1%, all other flights are allocated an AI % greater (the actual value isn't important) than 1%.Now whenever i'm approaching or departing the London area, using a quick FSUIPC key assignment, i set my AI% to 1%. I still see all the relevant Stansted traffic but my system is no longer required to process traffic relevant to say, Heathrow or Gatwick. Result, at least 15-20% fps improvement.When departing Stansted, once i'm about 50 miles away, i just reset the AI % back to 100% and all flights are returned.This methods does require that every flightplan that i add has to be editted so that only those flights relevent to Stansted contain 1% AI, every thing else gets replaced (via a simple text editor's search & replace feature) to 2%.Gary

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I like your style Gary! "...thinking outside of the box" :-beerchug

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Hi Gary,The original question in this thread was if there was a limit to the number of active AIs flying around. Reggie said no but he highlighted an indirect and structural performance/stutter issue in relation to the (in)availability of sufficient AI parking catagory/capacities at airports in a radius of about 108 Nm. from a user aircraft. It transpires that this 316 Nm. diameter circle even moves, with your user aircraft in it's center, as you fly anywhere in the world at whatever altitude or speed.In other words, frame rate variations can occur when the AI engine activates and de-activates (far out of sight) AI movements as the circumference of this circle moves across airports on the ground. Under normal flying conditions at higher altitudes these frame rate variations should not be noticable especially when you have set your frame rates to a maximum. However, at lower altitudes near e.g. "heavy" addon airports with many active AIs, this issue can get so bad that even the default ATC gets overloaded and visible stuttering (= very high frame rate variations) can occur.I agree with you that certain user tricks can be devised in order to lessen this performance issue, the most drastic one being to reduce the AI% to zero but my personal opinion is that anything in that direction will effectivly reduce my flying experience especially as I fly all over the world with a hugely expanded FS9. It all boils down to a question of personal taste but my "wait" (as I have done before) is for a much faster processor/mother board/chipset/memory/Mack truck radiator combination which seems for the moment to be the only real way out, also for FSX and the possible FS11 which Reggie mentions.In the meantime a lot of us will just have to accept the existing hardware limitations and keep watching this forum for good ideas.Your input is appreciated, as is Reggie's.RegardsHans

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