Austin, Ben and I are still working on cleaning out the remainder of Ultra-High priority bugs right now which essentially consist of crashes or other things that impact large groups of people. Only once these types of problems are taken care of will we be able to start looking into figuring out what can be optimized in the sim.

Many of you are getting really decent performance. Many of you are getting “ok” performance and others are getting really poor performance. This is not a surprise because there is a huge spectrum of hardware out there. Moving forward, we have some tools at our disposal that we can use to collect some data see what’s impacting performance the most. Then we can optimize it. Then we can see what the second biggest problem is, and then optimize that….and around and around we go.

In my opinion, one major contributor to performance loss right now is having your settings wrong. X-Plane allows you to configure a LOT of settings to get optimal performance. We’ve given you more than enough rope to hang yourself with, and many of you are doing just that. X-Plane’s rendering engine is very flexible. It has to be because it has to run on a huge spectrum of hardware. Like any large system, it needs to be tuned properly for its intended use. Ben’s already told you that you need to hit rock bottom to tune X-Plane properly. What that means is that you need a baseline. Think of how you tune a guitar or any instrument for that matter. You need a reference pitch such as a tuning fork. You match one string up perfectly to that pitch and then you adjust ONE string at a time until it’s in tune with the previous string. Imagine trying to tune a guitar without a reference pitch. You would have no idea whether you were making progress or not!

The “tuning fork” of X-Plane is starting from zero. This is your reference. Turn off EVERYTHING. Turn of AI aircraft, set your clouds to clear, set your visibility to something reasonable like 20-30SM, turn off rain and storms. Go to your Rendering Options and set EVERYTHING as low as it will go. If you run X-Plane in fullscreen mode, turn down your resolution. If you run X-Plane as a window, reduce the size of the window. The item that says “Framerate-lock to monitor” should be set to “Do Not Lock” (more on this in a moment). Take a look at what kind of framerate you get in the sim. Don’t just sit on the runway, fly around, take note of the range that you see. Also, see what you’re system’s doing as well as you can. Take a note of CPU usage, Memory Usage (mainly how much is left to be used), and GPU usage if you have a fancy driver that lets you see this information. At this point, you should have a rough guess as to what your weakest link is. If your CPU is almost maxed out right now, it’s going to be your limiting piece of hardware. If your almost out of memory, that will be your limit etc.

(A quick detour on CPU cores…more is better-ish…to a point. 9 women can get together and do 9 different tasks in 1/9th of the amount of time it would take 1 woman, but 9 women cannot have a baby in 1 month! The point is, if X-Plane has multiple tasks going on (like AI traffic, scenery pre-loading etc), then multiple cores helps get the tasks done quicker. But if there’s only one task going on (like rendering), your other cores will NOT help you do it any faster.)

Back to tuning…Start with Rendering Options. Now start turning things up ONE setting at a time. Start with things that are most important to you. Each time you change something, go back to the sim and see how it impacted you. Take note of your hardware utilization again. Has CPU changed much? Has memory changed much? Don’t be fooled by large jumps in FPS. Remember, going from 100fps to 90fps is a difference of 10fps (“wow” you’re thinking)…but that’s only 10%! That same 10% reduction at 20fps would bring you down to 18fps. You should care about the PERCENTAGE change, not the FPS change. If you notice that one setting in particular causes your framerate to lose a huge percentage, then you’ve probably figured out what the weakest part of your particular hardware is. This is the setting that you’ll either have to live without or the one you’ll have to be VERY careful about touching. If this setting is important to you, perhaps there is something else that you can sacrifice to get some performance back for this setting. Or if you’re able to upgrade your hardware, that’s the thing that you should invest in.

At some point, hopefully you’ve found yourself with a configuration that you like. Again, note your average FPS in various situations. NOW you can go back and set the weather how you like it. Turn the clouds up, turn the visibility up if you want but be careful. Visibility can be a huge factor in performance. The farther you can see, the more things the system has to draw. I would not recommend going over 50SM unless you find yourself with a ton of performance left over. Now you can turn on the number of AI planes that you like flying around with. You may have to go back and retune some things to get the system balanced with the new weather and AI. Make SMALL incremental changes. You don’t want to de-tune it severely. When everything’s balanced, now go back into Rendering Options and note at the very bottom, it will tell you how much VRAM is being used. Turn the Texture Resolution up until the VRAM usage gets near the amount of VRAM you have on your GPU. Then fly around and test it. You should NOT notice any difference in performance. If you do, go back and turn your Texture resolution down a notch and try again. Your goal is to get your texture resolution as high as you can without impacting performance or going over your VRAM limit.

Lastly, a note on VSync. I told you earlier that the “Framerate-Lock to Monitor” setting should ALWAYS be on “Do Not Lock”. This is a tiny white lie. If you’re an advanced user, if you know what VSync is, if you know how it works and if you have enough performance to spare and you want to stop scene tearing, go ahead and turn it on. Even then, don’t turn it on until you are done tuning framerate, because VSync will obscure changes in fps, making it impossible to tell what effect a rendering setting has on your hardware. If you don’t know what it is or what problem it’s meant to solve…please leave it off and forget it exists. It will NOT improve your performance. If you’re like me and just want to learn about it anyway, read this but leave the setting off anyway.

Feature Affected Subsystem
AI Aircraft CPU/VRAM/Bus Bandwidth
Cars CPU
Clouds GPU
Objects Bus Bandwidth (CPU on old cards)
Roads Bus Bandwidth
Forests Bus Bandwidth
Screen Resolution / Window Size GPU (usage proportional to resolution)
Shadows Bus Bandwidth (this amplifies all other bus bandwidth use a lot!)
Table 1. Feature vs. Affected Subsystem

***EDIT*** I didn’t want to have to do this but I’m going to be more heavy handed with the comment moderation because inevitably, the comments end up getting WAY off topic.  Feel free to ask questions or post comments directly related to the topic but this is not the forum for other discussions. I am also not going to be providing one-on-one tuning at this time so please do not post your specs unless asked. We have not begun diving into performance issues yet. The purpose of this post is to educate you on how to setup your own system in the most optimal way possible right now. Thank you for your understanding!

About Chris Serio

Chris is an electrical engineer and commercial pilot who got roped into software development by Ben because misery loves company.

37 comments on “Tips for better frame rates Pt #1

  1. Thanks Chris,

    I just want to add another factor, though it should be obvious: “Exit any application not relevant to the sim”. Close all browsers/office/image editing you name it, before tweaking performance, you can never know which “other” application is effecting the system.

  2. Could you tell us what options require a restart? It seems like I have to restart to get anything to take effect. I have a feeling it’s more placebo than anything that makes me restart it for some changes so it would be nice to have a full list. It would cut the time spent troubleshooting, since it takes the sim 3-4 minutes to load on my machine.

    1. To my knowledge, texture resolution, anti-aliasing, gamma, texture compression and possibly “framerate lock” aka. VSync (which should be off!!).

  3. Hello

    My limiting Hardware is the Graphiccard.
    I’vd got 1 GB Ram. In “rendering options” ist X-PLane Indicates 350 mb of vram use.
    When i look at the cards Memory Usage, it shows 980 mb. Why does X-Plane only indicates 350? I have no other application running in the backround. So X-Plane should be the only VRAM user at the moment.

    Please help!

    1. A few possible reasons:
      – X-Plane shows textures managed by the GPU – that includes textures we render to and textures we upload. They may not all be in VRAM.
      – X-Plane does not show VRAM used by meshes, nor does it show VRAM used by ancillary structures not directly requested by X-Plane but necessary to render. (Nerds: that would be things like a hierarchial Z buffer..X-Plane knows about the final rendering surface but not the extra index memory.)
      – X-Plane does not show VRAM used for the final rendering window – only offscreen render-to is included.
      – X-Plane isn’t the only client of VRAM – the window manager is in there too.

  4. Bravo gentlemen, bravo. I can’t wait till v10 has been optimized and painted up to the point that all 4 cores start to spew smoke.

    Is anyone aware of a real-time method of quantifying bus usage in the form of a discrete number or percentage (i.e. not just a scenery tweak here and there to guess at when it’s been maxed out)? Either win 7 or linux or both?

  5. HI Chris,
    Thank you very much for the advice. I’ve been playing with the since it was introduced. I’m blown away by what you guys have done!

    It looks like the HDR option takes the biggest chunk out of my fps performance. (10 20fps) Ben mentioned in passing that the HDR may be “reworked” at some point. Are you guys at this time able to give an guesstimation on what kind of fps increases you will be able to squeeze out by optimizing the HDR code.

    My computer is an i950 and I’m running the GTX 570 with 6gb of ram. I know this might be asking for miracles but if somehow you guys could squeeze another 8-10fps out of the HDR option it would really save alot of users having to upgrade to get into the consistent 30fps in graphically intensive areas like a city or detailed airport with mid to mid high render settings. 30fps in XP is a completely different and smooth visual compared to the competitor’s sim.


    1. Hi Craig, HDR is a known source of strain on a GPU. This isn’t a bug, this is a side effect of the amount of work it has to do to accomplish its goal. It’s possible that there’s some performance enhancements we could do but we’re not looking or thinking about that kind of thing yet.

  6. Is triple buffering available in XP10? If so, what is your impression of using it, is it working as expected?

      1. Uh? I think triple buffering is available on all card since decades… Could you ask Ben if it’s supported?

        1. It is a driver/control panel thing. As far as I know there’s no OpenGL access to it – even OS specific.

          On my NV/win box, enabling triple-buffering in the driver does appear to restore some fps in vsync mode. So we don’t appear to do anything that kills it. But my results with the driver control panel are inconsistent enough that I don’t know how much I trust them.

  7. Thanks, Chris. This is a brilliant bit of writing and guiding. I will follow your instructions to the letter!

  8. Hello,

    I have managed to adjust the settings on my system perfectly with the above tips. It looks wonderful and runs smoothly. However, as soon as I climb higher then 10.0o0ft or 15.000ft my frame rates drop to 12-15fps. No matter what settings I choose the rates won’t go higher at high altitudes.

    Also on my computer no fog gets introduced if frame rates get lower. Is this a setting? I cannot seem to find it in the manual or the menu’s


    1. As you go up in altitude, visibility increases putting more strain on your system. That’s normal. “Fogging” to reduce visibility is no longer a feature in v10. There are technical reasons why it’s just not as useful as it used to be.

      1. Thank you Chris,

        But what can I do if I cannot get a higher framerate above 10.000ft even at the lowest rendering settings? My system should be able to run the software very well and it does at lower altitudes.


  9. Well, what can I say … frame rates almost doubled with the new patch!
    That was me with my Nvidia 9400M and the fillrate problems.

    Were you rendering the scene twice per frame? It almost feels so.

    Right on, commander

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  11. Thanks for all the updates, guys. We really appreciate the communication, especially cause we know you all are so busy.

    Just wondering, what puts a load on RAM, vs VRAM? I’ve got 8GB of RAM, with usually over 4GB totally free, but X-Plane never seems to use more than 1GB.

    Also, I can’t get more than 35 fps with everything turned down to zero. That’s on a 2010 MacBook Pro, OSX 10.6.8 (Lion is terrible, definitely skipping it), i7 at 2.66GHz, 330M with 512MB VRAM…I should be getting more than that, right? I’ve noticed the CPU hardly breaking 100% on X-Plane, which seems a little odd…are other aircraft the only part that’s multi-threaded?

    1. I am having such a hard time trying to figure out why there are so many apple users using XP. The good thing with apple is they do make good looking computers with great software. But their computers really are not meant to be playing hard core machines. Not even close. And then even running XP10 on a macintosh laptop? People, if you need performance and compatibility go for a good PC. It will probably cost you one third of the macintosh equivalent but perform twice as good.

      I do not like ranting, but geez. Expecting very high graphics performance of a computer mainly designed to handle CPU intensive OS apps is just… well… if gaming or simulation is what you originally were looking for when buying the computer, then I do not know if you did the right choice in choosing mac…

      1. “if gaming or simulation is what you originally were looking for when buying the computer, then I do not know if you did the right choice in choosing mac.”

        I wasn’t. 😉 There are many other reasons to get a mac. Having it run X-Plane is a bonus, not a requirement. My planned Ivy Bridge/Kepler (hopefully) build next summer will be my dedicated X-Plane box.

        The reason there are so many Apple users running XP is because there are no other flight sims available for OSX. We buy Apple for other reasons primarily, then run XP. Of course no one would recommend getting an Apple machine with the primary intention of running XP.

        But back to my original question…the i7 is solid, as is the 330M with 512MB of GDDR3. I feel like I should be getting more than that at zero settings.

  12. Hi,

    thanks for the great information here. I was able to tune my visuals nicely now. It is/was such a pain to fiddle around with FSX as the impact of changes are totally unclear.

    Some remarks. Only few will find this information here. Please embed this into the UI. You might categorize the settings according CPU/GPU impact.

    Please reduce the options. If there are settings that normally should be left on/off, then remove them from the UI. Less settings -> less questions -> less complains -> less support -> more flying.

    In general, i strongly recommend to simplify the user experience. Many UIs might be relevant for developing / suporting the software, but most likely not for me as customer. It is not only irritating, it destroys the imersion you generate with the truely amazing graphics… Less is more!

    1. Wow, I can’t disagree with this more. Less is more? You want to head over to Microsoft Flight Simulator X then. X-Plane is all about giving the users power and control. That’s what it has always been about and hopefully will remain so. X-Plane offers so much tweak-ability for everyone, which is why it has been so successful. You have to spend the time tweaking, as Ben recommends. Start with all options off, and go from there. Learn what each one does, it’s part of the fun of X-Plane man!

  13. This is a lot of work. Can I just play around with the settings haphazardly and bitch about it when I get poor framerates?

  14. I have an imac mid 2011 and I’m very happy with my settings and the fps even though I have to give up a few things totally like HDR, and water reflections, my clouds details are at 24% only. The fps I get go from 32-39 on the runway going up to 75 when airborne, I get even better results in a night flight. The only problem which is particularly irritating is a big stutter the second I take off and there are clouds, this happens only in the daylight, in that split second that I pull the yoke to take off the system is probably starting to process the clouds and my fps, for a fraction of half a second drops from 32-39 to 13!!! Then goes immediately to 45 and when passing again through clouds it drops to 24 no stuttering anymore. IMHO is clear to me that the clouds are a weak point in my system but I hope there will be some improvement here, my settings for the clouds are 24% detail 40% size puff 40% opacity.

  15. These are excellent hints! I tracked down all performance effects today and got very sup rising results – for example that my system does not care about high texture resolution quality or AI Aircraft, but does not like high settings on the Anisotropic Filtering at all.

  16. thanks for this post. I did exactly as described. However, I still think there is a problem with X-plane 10. I am running the latest version 10.03b. I have 8 cores all running below 50% average, and GPU never exceeds 75% usage with HDR on. I get 30 fps at KSEA sitting on ground blue skies. As soon as I reach 4000-5000 feet, FPS descent to 10!!!! 10-12 fps. GPU is the same as well as CPU. there is definitely something wrong. I can’t be out of RAM for sure.. I have WAY more than 4 gb.

    If I put everything to default, and HDR on, and 40% clouds, I still can’t MAX the GPU Activity, nor the CPU activity, nor the memory ? How am I supposed to find the “bottleneck” ?????

    1. No one’s denying that there may be something that can/should/will be improved in the sim. You did exactly what you’re supposed to and you now know that your bottleneck is not your CPU or GPU or RAM…so perhaps it’s bus bandwidth. You can try to reduce things that consume bus bandwidth. This also means you can INCREASE your settings so that you consumer more CPU/GPU and make the sim “prettier” without hurting performance so long as you don’t increase bus traffic. We’ll be getting to performance tuning soon where we can talk in more specifics and we’ll have tools to help figure out what’s going on.

  17. Will X-Plane 10 ever run crossfire? I bought a 6850 ATI the other day and didnt help much. Also will it ever be upgraded to run faster with the current hardware? I thought X-Plane 10 was supposed to run at max settings with atleast 1GB of VRAM.

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  19. Quick question.

    What is the difference between F-SIm and F-ACT in the frame rate display. that is new. also, my F-Sim is stucked at 19.0 always, while the F-ACT is very low. I’ve seen the F-SIM go up above 19 only once. Even at very very low settings it still shows 19


  20. OK. I tried it again. This post will be an optimistic one, contrary to the previous ones I made.

    I noticed a few things that I haven’t seen mentioned anywhere yet on the forums. A few more observations:

    – The sim seems to perform BETTER when NOT using the Cessna 172. For example, sitting in KSEA in a B747 gets me 19fps. In same conditions, loading up the C172 gets me 15 fps. Very strange. IN flight the different is even worse.

    – The sim is not constant in the fps. Something changes as the simulation advances in time. I can takeoff at 20 fps, climb and as the sim goes and goes, and as my flight advances, the frame rate drops as if something was stucked in some kind of loop.

    – Changing the 3D view to look at my seat only (no external view at all), DOES NOT IMPROVE THE FRAME RATE at all. Very strange and you probably have a point of optimization right there. Version 9 would increase the frame rate by a lot when the view changes to just inside the plane vs. external. This is very strange because the frame rate does go from 19fps to 60fps in clouds.

    – The F-sim and F-ACT is very confusing. The F-SIM is constantly sitting at 19.90 fps. However, I’ve seen it climb by stutters to 20 and even 23, only to drop back to 19.90 again, stable for 10 minutes or so. What causes the F-sim to go up like that??? Even with F-ACT being 24 fps, the F-sim stayed at 19.90. There is some loops that are not working properly. I have looked at the log.txt after. There are a lot of errors all over the place. Error finding this, error finding that, etc. That’s after a brand new installation of the demo. (last night)

    – Flying faster seems to be getting more fps. Strange, completely the opposite of FSX. FSX, the faster you went, the more the computer struggled to display the same amount of things in less time. In X-plane 10, flying faster provided me with faster fps.

    – I’m repeating myself here but, something is blocking the fps from going up, even if the GPU is not used to its maximum and the CPU either.

    I think I’m confident things will improve a lot in the near future.


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