Locked Frames. . .a Myth?

[falcon409]

We have all battled the elusive perfect frame rate setting and one in particular has been more elusive than anything else. That would be the myth (my opinion) that locking the frame rates at a particular setting will keep them at that setting until you change it, or fly over NYC.

Note: for the record, my vid card is an NVidia 9600GT w/512mem and the latest (258) driver
CPU is a 3.0ghz on a Gigabyte 5600+ Motherboard and 8gig of memory

I have read countless posts from individuals who state, "I have mine locked at 25(insert your preferred claim here)fps and they're rock steady". FS9 was never a problem, I had that baby humming with everything maxed and flight was smooth as silk. FSX, for obvious reasons, has been an entirely different scenario and "locking" any fps has been a joke. The word "locked" infers that something is unable to move or be moved, but I have never "locked" my frame rate at anything where it remained there for more than a few milliseconds. Now I have to say, that in a way. . .maybe it does remained locked. . .in that it never goes above that number, lol, but if I lock it at 25fps. . .it will run the gamut of fps from 25 to 4 and back again depending on what I'm flying over at the time. I've been running FSX with the FPS set to unlimited, which only gives you a false sense of the sublime because at any time you might look at the counter and see it's actually at 10, and not 50, like it was 10 seconds ago. lol

So, as much as I hate to do this, I'd like to know what everyone else thinks (I know. . .the possibilities are endless).:salute:

[Headwind]

I'm with you there. I have noticed that I can fly over city or in the middle of nowhere and it will stay about the same fps. However no matter what it still fluctuates. I can be flying over a desert and say I have my fps slider at 30 it goes from 30 to 10 to 22 to 30 to 28. Granted large cities are different but still the same. I'll go from 30 to 14...ect...

I personally think FSX has a brain of it's own and likes to play games with us like a kid...hehehe

I can fly one day and everything is hunky dory and the next I have horrible fps. The following day same place and time in FSX and I have brillant fsp...lol I think it must be a 2nd cousin to my wife and has the same temperment as her...hehehe

Just kidding my wife is great and I wouldn't be able to find the door some days without her.

[Bjoern]

A frame lock at 30 FPS won't see you exceeding 30, but everything from 0 to 30 is still possible.

I found 30 to work very well; on my old system I even had it only at 20 and it did the trick. Still seeing only 8 to 10 at large airports though. Damn AI...

[gradyhappyg]

People get too hung up on the framerates. If it's smooth no hangs no stutter then don't worry bout the frame rates. I've seen severel people mess up a perfectly good FSX install cause they are only getting 20-30 frames per and they read somewhere some guy was getting 60 or better. If it's smooth just relax and leave that pesky shift/Z alone.

[LonelyplanetXO]

I may be wrong but I think the idea behind locked framerates is that if you pick a locked number FS will attempt to maintain the selected FPS number by reducing peripheral settings such as scenery rendering. yes the FPS will still vary on the counter and in heavy scenery will drop presumably because it can't reduce individual settings fast enough to maintain your choice.
For example with my fps locked at 25 I see beautiful scenery in non-city areas but get a bit of blurries in denser urban areas, but the frames remain smooth. Fly over NYC and FPS counter drops, blurries set in and eventually the sim starts to stutter as the hardware is overwhelmed.
Leaving it unlocked doesn't change much, but does create one issue for me - I get micro-stutters fairly consistently. So my choice is locked, not because it stays steady at 25 - you're right, it doesn't. But it does avoid those stutters in all but the densest scenery so provides overall, a smoother experience.
My PC isn't ideal and those with better hardware will doubtless get better results. My suggestion would be try unlocked first and then lock at a figure you feel happy with. Whichever provides the smoother experience on your PC, stick with it.

Perhaps one of our resident guru's can provide a better explanation?
LPXO

[guzler]

I've found that without it being locked, it spikes when it gets the opportunity (i7 920) massively, only to be dragged back down just as fast when panning etc. Those spikes appear to cause stutters, so fixing the frame rates does seem to help on my pc to reduce stutters.

[Major_Spittle]

Good post! I like the claims about having FSX locked at 30fps with everything Maxed out, then you find out that "everything" didn't include the Airport Ground Traffic setting which were on low, water effects at 2x low, or Airplane Traffic which was at zero.

I'm not sure if people post this stuff to make themselves feel better about their $2000 system or they maybe spent $2000 on a computer but only fly default aircraft/scenery and do get 30fps with everything maxed out? Perhaps they fly in a 2inch window on their screen?

I personally can get 20fps with some dips here with pretty high settings on most everything and low/mid on just a few things (airport traffic, water, no bloom, cloud draw distance/density). I know there is Payware that will drop my system to 4 fps around airports with the settings I run.

System: i920 @4.15, 6gb DDR3 1600, ATI 5830 @ 925

[Daube]

"Locked" ?
Who said "Locked" ?
In the French version of FSX at least, the title of the setting is "frequence d'images cible", which litterally means "Frames frequency target".
A target is something that is not always reached. It has never been a secret that FPS limit set at X means 'any value from 0 to X, depending on the flight conditions'.

[Lotus]

Where it says "Target frame rate" in the FSX display settings, it should really say "Frame rate cap". The sim won't drop your detail settings in order to try to hit that FPS, that's just the limit of how many frames per second it's allowed to display.

FSX is designed to use the remaining CPU time after a frame is rendered to load data and get it ready for the next frame, ground textures and such. If you have a target of 30 fps but your system can only pump out say 24 fps over a major city, FSX has no spare cpu cycles and the blurries start to creep in immediately. Keeping the action moving is the sim's number one priority and it'll keep doing that regardless of what happens scenery wise in the background.

Aside from the numerous tweaks available, some of which are great, your best bet is to set your fps target to a value that is below what your computer can consistently deliver over a dense scenery area. What I do is take a worst case scenario, flying over Tokyo or Seattle downtown etc, run unlimited, see what the lowest average FPS that my system can maintain is, and then set the FPS target to about 5 fps below that, which gives FSX some breathing room.

Some very minor FPS drops and variability are to be expected when running with an FPS limit in the sim, say 1-3 fps now and then, even if you are consistently hitting your target. These can be caused by any number of things, bad hard drive fragmentation, loading of very large textures (when flying into range of a very detailed addon airport for example), or having the fiber frame time fraction set too high.

Granted, it's all very system specific. Some people get great FPS and clear textures when running unlimited FPS. I never have, not once, across three different systems! For me the FPS just jumps around like a Jack Russell terrier, and the textures go on vacation. hehe.

-Mike

[mal998]

Here's food for thought...think back to when you first installed FSX...before all those tweeks and addons and aircraft. FSX ran fast and smooth, didn't she! Yes she did, and the more stuff we put in, the slower she got and the more stutters, pauses and micro-stutters we began to see...right?

Well, I believe that, is really the bigger issue with FSX. Performance of the basic program degrades over time as we add more and more "stuff" into the sim, and that the only way back to flight sim "Nirvana" is the dreaded clean install.

Don't get me wrong, I am not suggesting or prescribing or recommending fresh install as a fix or tweek. We all know what a pain in the arse that can be...re-building the world...ugh!

It's just my observation after having tried just about every tweak under the cyber sun, the latest being the Frame Rate Limiter.

Your thoughts Gentlemen...

[falcon409]

Good post! I like the claims about having FSX locked at 30fps with everything Maxed out, then you find out that "everything" didn't include the Airport Ground Traffic setting which were on low, water effects at 2x low, or Airplane Traffic which was at zero.

I'm not sure if people post this stuff to make themselves feel better about their $2000 system or they maybe spent $2000 on a computer but only fly default aircraft/scenery and do get 30fps with everything maxed out? Perhaps they fly in a 2inch window on their screen?. . . . . .
Yep, I agree!

[falcon409]

. . . . .Aside from the numerous tweaks available, some of which are great, your best bet is to set your fps target to a value that is below what your computer can consistently deliver over a dense scenery area. What I do is take a worst case scenario, flying over Tokyo or Seattle downtown etc, run unlimited, see what the lowest average FPS that my system can maintain is, and then set the FPS target to about 5 fps below that, which gives FSX some breathing room. . . . . .

-Mike
See, I couldn't use that Mike cause my lowest average would be around 5 which puts my FPS target at "0", lol.

[Ferry_vO]

I have mine 'locked' at 24; I tried setting it to 'unlimited' but I would get a framerate somewhere from below ten to over one hundred and a lot of stutters. If I lock it to 20 fps the framerate will stay at about 13 fps for some reason! 24-25 fps seems to be a good number as it keeps it almost always at 25 unless I fly over dense scenery areas, then it will drop to 16-18 fps.

[falcon409]

. . . . . . .or having the fiber frame time fraction set too high. . . . . .

-Mike
The what? lol. . .I don't have that in the cfg file Mike

[Major_Spittle]

The what? lol. . .I don't have that in the cfg file Mike

fiber frame time fraction has a huge impact on my system. I run it between .1 and .2 for the most part.

It keeps the things running quick and smooth but the trade off is that I will get blurry autogen that fills in over time in area that would typically choke out my system down to 8-12fps.

Good Reading about how FSX, the CPU, and the Video card work together to give you such poor performance. http://www.hovercontrol.com/artman/publish/article_122.shtml


FIBER_FRAME_TIME_FRACTION=n
[ n = 0.01 - 0.99 ]

This variable determines the amount of CPU time given to loading scenery data as a fraction of the time spent rendering. For example, the default value of 0.33 means that for every 3 milliseconds spent rendering, FS will give 1 millisecond to the scenery loader. If necessary, you can use a larger value to devote more time to loading (any number between 0.01 and 0.99). Or, if you don't have a problem with the blurries and you want slightly higher frame rates, then you can use a smaller value.

Should you choose to use this "tweak", here's how to do it: Insert a line directly under the [MAIN] section and enter

[michael davies]

Frames rates have an effect on animations, certainly on helos, lock at 20 or 24 and look how stuttery main rotors are (certainly here), then lock to 30 and see them suddenly fluid ?.

Personally I find locked at 30 helps overall, I can sometimes run unlimited and get nearly 100, but the odd spike to 20 or 140 just makes it stutter like mad, thus set to 30 seems to even it all out....for me.

Best

Michael

[Roger]

Frames rates have an effect on animations, certainly on helos, lock at 20 or 24 and look how stuttery main rotors are (certainly here), then lock to 30 and see them suddenly fluid ?.

Personally I find locked at 30 helps overall, I can sometimes run unlimited and get nearly 100, but the odd spike to 20 or 140 just makes it stutter like mad, thus set to 30 seems to even it all out....for me.

Best

Michael

Same for me Michael.

[Dimus]

I am using the FPS limiter in my install with very good results I must admit. You may find it here:

http://rapidshare.com/files/160642187/FPS_Limiter_0.2.rar

I have set the FPS to unlimited within the game and always run FSX through the bat file created by the limiter. I have set a lock of 24 FPS and it works well in my rig which is very similar to yours falcon. I also have followed Nick Needham's tweaking guide to the letter and it generally works well and stutter free if I don't go asking for trouble.

[Daube]

Here's food for thought...think back to when you first installed FSX...before all those tweeks and addons and aircraft. FSX ran fast and smooth, didn't she! Yes she did, and the more stuff we put in, the slower she got and the more stutters, pauses and micro-stutters we began to see...right?


No, not AT ALL.
Reason is simple: when I first installed FSX, it had a basic FSX.CFG which:
- allowed the usage of the bufferpools, which is very bad for my graphic card
- allowed to draw 4000 trees and 4000 buildings per cell, which is VERY BAD for my CPU, and caused graphic spikes all around
- set the texture_bandwith_mult to 40 per defaut, which is bad for my graphic card
- etc....

No need to say more. Without tweaks, my FSX ran like cr*p.

[falcon409]

Here's food for thought...think back to when you first installed FSX...before all those tweeks and addons and aircraft. FSX ran fast and smooth, didn't she! Yes she did, and the more stuff we put in, the slower she got and the more stutters, pauses and micro-stutters we began to see...right? . . . . . .

Your thoughts Gentlemen...
Afraid not mal998, as a matter of fact, when FSX was first released, what you heard more often than not was. . ."I'm going back to FS9 until MS figures this "crap" sim out and get's it running so that the average Joe can enjoy it". I was one of those who gave up on it early and went back to FS9 until I added a better Vid Card and some additional memory. Even with that, and only running default scenery and aircraft, it was an uphill battle to get any enjoyment out of the sim. There's an entire forum for FS9 folks that will tell you what they thought of FSX "out of the box".
So I'm another who doesn't really agree that it's the fault of all the addons we've piled into the sim that has caused the problems we have. Of course that just my opinion.:salute:

[AndyE1976]

As has been previously stated, it's a target frame rate, not a locked frame rate. Setting a target means that you free up CPU cycles for other things and generally get a more consistent frame rate.

Personally I run with a target of 18, which seems to work well with a good balance of autogen, AI traffic and scenery density. It all falls to pieces though if I get near London X with the Horizon Photoscenery and a complex aircraft though. Which is why I'm evaluating building a new rig next year.

Addons do cause the sim to run slower, but mainly due to the poor way that FSX indexes - it routinely takes me 10-15mins to load the sim, select a plane and airport and load onto the runway. A good chunk of that time is simply waiting for the aircraft select window to open or the airport select window to open/close. Both operations that should be instant, except FSX doesn't maintain proper indexes and is loading things it doesn't need prior to me selecting 'Fly Now'.

There is a huge amount of room for improvement in the UI and game engine, which hopefully a new version of FS will address whilst retaining compatibility with FSX addons.

[heywooood]

correct Andy
FSX is poorly optimized (if it was optimized at all) by m/s....which is in keeping with the general appraisal of the populace wrt m/s optimizing ANY program they put out.


it could run so much better if certain things were prioritized or indexed better - but I doubt m/s will revisit flight simulator anytime soon...and since they don't like to give stuff away I'm afraid the only thing third party dev's can do is try to get their products as streamlined as possible so as to utilize the things FSX offers as best they can without using too much resources or CPU cycles to render within FSX's nasty framework.

[Bjoern]

There's an entire forum for FS9 folks that will tell you what they thought of FSX "out of the box".

FSX RTM was a POS in terms of efficiency.

SP1 was an absolute necessity to make the sim enjoyable.




FSX is poorly optimized (if it was optimized at all) by m/s...

...because the FS9 users spoilt with hundreds of $ worth of add-ons needed backwards compatibility at all costs.

If it hadn't been for the ability to use stuff from FS9, FSX would have run *way* better from the start.

[n4gix]

Mike is absolutely spot on with the technical details. I would point out however that SP1 and especially SP2/Acceleration has somewhat diminished the actual purpose of the "target frame-rate lock," since many of the fibers that were previously auto-throttled by it have been spun off onto separate threads which are shifted to other cores (if available).

[AndyE1976]

...because the FS9 users spoilt with hundreds of $ worth of add-ons needed backwards compatibility at all costs.

If it hadn't been for the ability to use stuff from FS9, FSX would have run *way* better from the start.

I think that is always going to be a problem. I've got too much invested in FSX now to just abandon ship because they bring out something slightly shinier. However, backward compatibility is not necessarily a reason for inefficiency.

MS could have not supported FS9 aircraft in FSX and made more money by selling some features of FSX as addons or FS9, or provided an object convertor or added conditional logic to the code to branch to less optimized code for FS9 aircraft that couldn't take advantage of all of the FSX bells and whistles.

It's all wishful thinking though, it is what it is and it's not going to change any time soon.

[Bjoern]

However, backward compatibility is not necessarily a reason for inefficiency.

Depends on the extensiveness of the modifications. As of SP2/Acc, the gap between FS9 and FSX (native) is huge.

As you've said, what *could* have been done was offering a *real* model converter converting FS9 code to FSX code with the SDK but I guess that would have been too much for the FSX team to handle in time.


It's all wishful thinking though, it is what it is and it's not going to change any time soon.

Well, with Model Converter X, we're off on a good start. Conversion of scenery objects is possible with it and I really, really hope it'll get animation compatibility one day and the ability to read FS9 aircraft .mdls.

Granted, those aircraft wouldn't have stuff like bump or specular maps, but FSX's model format will totally do the trick.

AI with mimimal frame rate hit...*Dreams away*