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Geofa

Stuttering and FSX - a few idle thoughts.

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I was experimenting recently with the TEXTURE_BANDWIDTH_MULT setting in FSX.cfg in an effort to try and reduce those intermittent stutters (not the ones induced by data loading from HD).I went all the way up from values of 0 to 400 in increments of 5.I created a flight situation where the trike was flying around in a stable circle at around 200ft at Friday Harbour. Time midday, Summer.2 configuration files were saved in the sim - one, File (A), with an unchanging value for TEXTURE_BANDWIDTH_MULT=400 and the other, File (:(, where the values were being changed between tests. This file remained open on the desktop and saved each time a change was made. Both files were accessed within the continuously running sim.After each test with File (:( I would reload file (A) and what was very apparent was the consistent severe periodic stuttering when the value was 400.In the end I could not find a sweet spot with absolutely no stuttering but did find the best value for MY system turned out to be 30. When FSX first created FSX.cfg the default value was 40. I tested with the Extra at around 180kts flying low over the terrain in overhead spot view and the experience was quite exhilarating with minimal stuttering only really noted occasionally during turns.Now, like many of you, I have been down those well worn routes of eliminating background stuff and, indeed, I have a Hardware Profile created just for the purpose of Simming and Gaming with minimal services running and no unnecessary backround programs running. However, I often find myself running the sim from my normal Hardware Profile and, to be honest, really see little difference in the sim's behaviour. So there is usually very little incentive for me to reboot into the Simming and Gaming profile.My conclusion is that this issue is all down to data transfer rates and the relative capabilities of the CPU and GPU and whether these components are in fact matched together for optimum performance. The fact that so many of us are experiencing this problem in FSX and now, to a lesser degree in FS9, would appear to confirm this. Memory may also be playing a part here - faster may not necessarily be better.It's perhaps also worth reminding ourselves that we are not seeing this in other games, or at least not to the same degree, but then this could be due to the volume of data involved. A huge amount of processing is going on in FSX and it may be that at times there is just too much for the subsystems to handle without intermittent bottlenecking (stuttering).I think it would be nice if we could have a table of components which , if installed in a particular system, would lead to the creation of a balanced and powerful setup that could handle efficiently all that currently available software can throw at it. Sadly, that's unlikely to happen in the short term, which is a pity.Instead, we are left struggling to search for that ever-elusive sweet spot by constantly juggling with sliders and parameter values in the vain hope that we can somehow smooth/control the data load being presented to our wonderful new (or not so new) CPUs and GPUs. It's really a thankless and, frankly, frustrating task, but we doggedly persist nonetheless. Some have been lucky and we all yearn for their magic bullet. For most, however, that solution will never appear and eventually we come to terms with what often appears to be an impossible goal. That's the point when you put those frustrations to the back of your mind, accept the compromises which need to be made, and begin to enjoy the sim.MikeASRock 939Dual-SATA2, AMD Athlon 64X2 4800+ (2400MHz)(Toledo), 2GB Crucial PC3200 DDR400 Ram 3-3-3-8 (2T)(Dual Channel), (PCI-E)Sapphire ATI Radeon X1950 Pro 512MB (Catalyst 7.10 WHQL), SB Audigy2 ZS Platinum (Drivers version 5.12.0001.1196 WHQL), Windows XP Home Edition (SP2), DirectX 9.0c

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Hi Mike!!I have tried most, if not all, the standard tweaks (with varied values) and I always end up returning to a clean FSX.cfg file. Granted, I have only a P4 3.46 single core, but I am of the opinion (based on my limited expertise) that FSX simply is what it is, and even most quad core systems exhibit some stuttering and/or blurries and at major airports with at least some traffic enabled. It is my hope that Aces will announce sometime prior to FSXI just what combination of hardware will run it optimally, with no stutters or blurries, and with all features enabled (not maxed).Also, many thanks for your help on the re-instate campaign!!! Bruce

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SET TBM to between 50 and 80, MAX. I run 80 but I also use very fast and high memory hardwareTBM is not doing what it did in FS9 there is more to itAbove 100 you are totally saturating the bus for no reason unless you have a HDD setup, video card and processor from 2010 :)

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"People might want to go back and reread Phil Taylor's June 2007 blog on the subject of TEXTURE_BANDWIDTH_MULT."Yes, Jeff, good advice and I am familiar with the content, but if we always accept what we are told without question then that pioneering spirit would soon die ;)In the event, I found out the hard way that Phil is right! Isn't he always? After all, he should be best placed to know what FSX can and cannot do, isn't he?I agree with Bruce. Let FSX create FSX.cfg with all the necessary parameter compromises, and then try hard not to do too much fiddling. You will soon rue the day as you set about destroying that unique balance which was designed, or at least intended to assure reasonable performance across a wide range of hardware. An impossible goal to achieve, but in this we should accept that the developers have been moderately successful under very difficult circumstances, much of which was beyond their control.We were given a great deal with FSX and arguably, with hindsight, it might have been better if FSX didn't offer as much as it does. Whatever they do with the next version we can only hope that 'Best Performance' will be the watchwords emblazoned on the Developers' minds as they go about the business of creating yet another wonderful simulator.Mike

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"I created a flight situation where the trike was flying around in a stable circle at around 200ft at Friday Harbour."That should have been 2000ft, if anyone wants to try it. Quite a useful exercise and if your sim is going to stutter then it certainly will in this situation. Set up your view in fixed Spot and from the side of the a/c.These are my basic Scenery settings at initial load:http://forums.avsim.net/user_files/184104.jpgMike

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>"People might want to go back and reread Phil Taylor's>June 2007 blog on the subject of TEXTURE_BANDWIDTH_MULT.">>Yes, Jeff, good advice and I am familiar with the content, but>if we always accept what we are told without question then>that pioneering spirit would soon die ;)I agree that you should not always accept what you are told (I rarely do), but I personally follow my own rule that you should "Assign the value you give to information or opinions based on the quality of the source". ;-)As I have met and spent quite a bit of time talking with Rafael Cintron (the ACES engineer which Phil quotes in his posting), and found him to be a very knowledgable and helpful person, I accepted the information as being of the highest quality.Jeff

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A similar slow circle at any high-detail airport would be a similar "torture" test.Take off at Seatac, fly 120 seconds towards downtown Seattle, turn in a continual bank, and this will swap out downtown Seattle for Mt Rainier and back in a loop as long as you maintain the bank.

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>A similar slow circle at any high-detail airport would be a>similar "torture" test.>>Take off at Seatac, fly 120 seconds towards downtown Seattle,>turn in a continual bank, and this will swap out downtown>Seattle for Mt Rainier and back in a loop as long as you>maintain the bank.This is the exact benchmark I use to tweak a system for the TBM and other values. I think I mentioned that to you in another forum some time agoThe flight is a good balance between scenery swap, autogen and traffic and although its not the highest load area to work with, it gets the system in line with most of the world. once the hardware is correctly set up and that flight has established the FSX settings, the rest is in trimming here and there for the area being flown... a bit higher for bush and a touch lower for places such as NYC, LA etc

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MikeInterestingly, I also run TEXTURE_BANDWIDTH_MULT at 30, and my hardware is very, very similar to yours.RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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Hi Rhett,Yes, I confess I don't fully understand what is going on here, but the reduction of the TBM value from 40 to 30 does smooth things out somewhat. Also, interestingly enough, charging over the landscape in the Extra at low level doesn't seem to have a noticeably negative affect on texture catchup and ground detail remains sharp.Clearly we have altered the rate of data flow/load in some way and, on our hardware at least, this is showing positive results :) Perhaps the higher value of 40 is tending to saturate the bandwidth (see: http://blogs.msdn.com/ptaylor/archive/2007...week-or-2.aspx) and the subsystems become the bottleneck and can't deliver the data fast enough to the graphics card.When I set my frame rate to unlimited I notice a tendency for the display (best seen with a/c movement) to 'surge' periodically and I am speculating that this may also be a reflection of the data handling process and an imbalance between the relative capabilities of the CPU and GPU. Anchoring the frame rate to 20 I find eliminates this, or rather it may still be there but becomes hardly noticeable. I'm way out of my depth here, but I wonder whether this is an opposite effect and the more powerful GPU is having to wait for data which is arriving in spurts while the bandwidth is undersaturated. Perhaps this explains why those of us who have more powerful CPUs are able to run smoothly with the slider set to unlimited.Phew! My brain is starting to hurt..LOL!Regards,Mike

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Excellent observations!You are thinking in the right direction!Most will want to keep the TBM in the range of where MS wants it, 30-40 but those on better hardware can expand on that, and, as the next gen hardware hits the market the TBM can be raised. If the current video adapter and supporting bus are top notch, bumping it up to 50-80 will provide results as long as the rest of the system is in balance with the FSX slidersI probably should have better qualified my statement. I sometimes forget that when I post such info not everyone is running quads on 768MB+ adapters, apologies. At the same time, over the last year I have seen even slower system benefit from finding the 'sweet-spot' for the TBM and the respective sliders. As for unlimited VS locked... I also see the same 'surge' under the conditions where I am outside a large urban area. If AG and scenery complexity at airports is not being factored in because I am in the boonies, a surge can be observed. In those cases I lock FR to 30 (1/2 LCD refresh rate and well within my spec for frames) In heavy hitting urban or within 50-100NM of large airports I will stutter @ locked 30 and set to unlimited. :)

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I noticed something recently that is very odd with this stuttering issue. I too suffer from the.. thee.. the... stut... stuttering issue. If I am in a helicopter and rotate left or right, I see severe stuttering, on the order of 5 fps(guestimating). Even though my FPS meter CLAIMS to be producing 30 FPS. However, if I pan view with the Joystick hat button left and right, (just panning my view). I see a very smooth pan. This makes no sense to me. The scenery itself is still panning across my view wheather I am rotating the entire airframe, or just my head. So... the question is... what is going on here?I have tried all fps tweaks, rebuildng fps.cfg texture bandwidth multi. fibre frame ad-nauseam and never have got rid of the stuttering. Maybe all of us should stop tweaking, and MS should hire some quality programmers? or better yet, intelligent management? there's a contridiction in terms. hiding behind the fact that FSX does alot of computations is idiotic. fs1.0 ran on a 286-16 mhz computer and had full gauges and graphics. It was updating a true flight paramater, (well.. as good as MS can do anyhow) and now we have systems running nearly a million times faster, and all we are gaining is some audio and graphics? this is progress?-Stampeep.s. did I open a can of worms?

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"unless you have a HDD setup, video card and processor from2010"Yep, gottem' on preorder, any year now. :)

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Hi stampee,"hiding behind the fact that FSX does alot of computations is idiotic. fs1.0 ran on a 286-16 mhz computer and had full gauges and graphics. It was updating a true flight paramater, (well.. as good as MS can do anyhow) and now we have systems running nearly a million times faster, and all we are gaining is some audio and graphics? this is progress?"Your tone suggests a mischievous side to your persona and in this instance, I'm sure you would be the first to acknowledge, such comments are really not very helpful.The comparison with FS1 will be seen by many others, including myself, as so fatuous that it leads us to suspect that you have an ulterior motive for joining this thread. If I am incorrect in my assumption then I apologise, but, nevertheless, would ask you to spend a minute or two reading this page to see just how mistaken you are in making such a rash statement:http://fshistory.simflight.com/fsh/index.htmYou cannot compare the two. To do so is just ridiculous.Have you ever taken time to stop and consider the unique nature of FSX? I doubt whether its complexity of delivery has any peers out there right now. What ACES have achieved in this product is little short of outstanding. The pressures to produce this version of our favourite sim must have seemed at times overwhelming and yet they have persisted through it all and delivered a very worthy product which arguably, in my judgement, tries to do far too much this time around. Nevertheless, there is something for everyone to explore and enjoy.Yes FSX is not perfect and yes it engenders its own share of frustrations; it is a unique project in progress which started all those years ago in 1980 with Bruce Artwick's FS1 on the Apple II. Each version has had its own set of problems and as the simulator's complexity has grown, so our community has faced these challenges head on and have shown great determination to find solutions for the benefit of all simmers. FSX is no different in that respect.Flight simming is our hobby and a major part of our hobby is taken up with our efforts to find ways to make each version of Flight Simulator work as well as it can given the restrictions imposed by our hardware. Some of us are better at doing this than others, but as a community we try to share our ideas for the common good. You can't blame or criticize ACES or, indeed, Microsoft for doing their collective best to deliver each version of the simulator in a form that allows such diverse and frequently ingenious 3rd Party interventions. Indeed, with FSX we are, for the first time, seeing the beginnings of very welcome cooperation and dialogue between us, the end users, and the development team. This is healthy, extremely encouraging and certainly bodes well for the future direction of the simulator.We have a very stable simulator which, since SP2, is now starting to show its true colours. It is my hope that after reading this you can see things in a somewhat different light and decide to come and join us in this wonderful and, at times, exciting and fulfilling hobby.Mike

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I see nothing at all insulting or untoward in his comments. Maybe we just don't take criticism of MS well?Brian

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" MS should hire some quality programmers? or better yet, intelligent management?"..is insulting to the ms members who frequent our board.We would like to continue a dialog with Ms developers as it is in all simmer's best interests.I'd rather lose a few that don't see it this way than lose the dialog which will make a better sim for all.http://www.mediafire.com/imgbnc.php/1b5baf...b9f427f694g.jpgMy blog:http://geofageofa.spaces.live.com/

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