Friday, November 23, 2007

X-Plane 9 Performance - Let's Wait a Little

When someone posts bad performance with X-Plane 900b2 vs. 864, the urge for me to respond is overwhelming. I spend a lot of time very carefully comparing old and new versions in controlled situations to make sure we haven't let any part of the engine get slower.

For now I will try to hold off - there are a few basic things we can do with beta 3 that will change not only the performance of the sim, but also how the rendering settings are organized.

For now a few immediate thoughts:
  • If you are looking at a new graphics card, don't plan your hardware purchases on the beta. Wait for a final build to evaluate.
  • There is no free lunch - settings that don't exist in v9 (volumetric fog, reflective water, forests) are going to cause lower fps than 864. (You could set the forest setting to "insane" in v864 with no penalty, as long as you had no forest add-ons installed.)
And finally, something I find myself saying over and over and over: there is no relationship between the fastest computer on the market today and the highest settings in X-Plane. We do not guarantee that the fastest computers can run x-plane "maxed out".

The highest rendering settings represent the most detailed output our engine can make, and the most data we have (based on what fits on the DVDs). We provide this very high rendering setting because:
  1. A user might want a lot of detail in one area and not others. You can run on "insane" roads if you leave the other settings dialed down, or reflective water can be on if you don't have a lot of objects or world LOD. So even if having ALL settings on maximum kills virtually any computer made today, having some settings on maximum can be useful.
  2. If you buy X-Plane 9 now you are entitled to every patch (and then you may use it long after the version run is over). So you might be using X-Plane 9 for 2, 3, or 4 years. Settings that are impossible to reach on today's hardware may be very usable on future computers.
So we do not penalize users who want some settings very high, or future users, by preventing you from setting the settings in any way you wish.

Please understand that the settings are not calibrated the same as X-Plane 8. If you set the rendering screen to look "as close" to x-plane 8 as possible, you are almost definitely not getting the same amount of detail (and the same load on hardware) as you were in 864. They are not comparable. Trust what you see out the window while flying, not what's on the rendering settings screen.


Pearlseattle said...

I love this approach, compliments!
I will see how the beta version which I just ordered runs on my current machine, and as I planned to build a new PC in 2008, it would be very nice to see somewhere a comparison of the performance of X-Plane using different hardware configurations. I would therefore like to ask if the program contains a "batch mode" which can be run by any person using standard settings (like low/medium/high detail), so that the results can be directly compared. As far as I remember this "batch mode" for version 8 is mentioned together with the command-line parameters in an earlier post of this blog.
Thanks a lot! said...

It occurs to me that some of the comments about poor frame rates may be due to gpu limitations. I say this because I'm in the G5 camp with the 5200 gpu. I recall you saying that these machines should not run with glsl on. When glsl is turned off my frame rate jumped to about 33 frames/sec. I hope that for future iterations you can carve out an exception for these sub par machines to run with no glsl automagically. Thanks for your posts!

Anonymous said...

the two new rendering settings fog and water are currently a bit hard on the performance. Sample Situation:

placed at EDHR, RW33 I get

about 200 FPS with both turned off
about 42 FPS with Fog
about 65 FPS with water
about 26 FPS with boot on

A drop from 200 to 26 - can this be true? There are hopefully optimisations coming in this area. Me wonders how you guys do test this stuff (on what hardware ...) ;)

Benjamin Supnik said...

pearlseattle: x-plane already contains a "batch" mode - search for --fps_test in this blog! Or rather, the v8 command-line test is still available for v9.

jonhay: you are totally right - the FX5200 should not be used with shaders. We will be providing settings to let you use the 5200 without shaders in a future beta update.

anon: there is a "dependency" in the rendering system when some of those advanced features are image must be drawn and then used relatively soon after. So when I see such a huge performance gap, I wonder if the problem is that the machine is waiting for completion of those images before it can proceed.

One of the reasons xp9 is beta right now is that we don't have a lot of video cards within the company (because there aren't that many of us). So we expect to see a lot of variation based on hardware. As we learn about gotchas like this in the hardware, hopefully we can optimize at least some of them.

Anonymous said...

Hey Ben!
Silly you said we were'nt going to see trees in xp9. The exact thing I asked about seems to have gotten there now :) And you said we were gonna have to download some 3rd party trees to get trees in xp. Now with trees in xp9, as I see the situation - there is only two things left to make the sim look wonders:

1. Make the forests look like forests.

Instead of throwing trees over the whole place, try to make some sort of engine that places trees in "formations" and "groups" so that it looks like in reality where trees grow in certain areas. This makes the sim look so real. Just look at msfx. So we need those woods to be more "patchy", where trees are then placed on earth surface that HAS THE COLOR of green. A "tree-engine" like this would make trees impossible to grow on vegetable (yellow) soil and therefor make the sim look more real to life.

2. Even more high-res groundtexture. With objects being the latest trend, flight simulators
' are looking so much like the real thing. The objects are already pretty highres but when you fly low or semi-low you realize the ground will have to be more highres for the trees to really "blend in". Otherwise it just looks like ehum, objects on a blurred flat lowres image. Highres textures with different sorts of ground and then placing trees on the green areas only would make a huge difference!

Anyway, thanks for your work. I have just seen some new screens of xp9 and I am thinking of getting a copy in the near future when bugs and that stuff is wiped out.

Cheers Ben!

Anonymous said...

anon here
[quote]One of the reasons xp9 is beta right now is that we don't have a lot of video cards within the company (because there aren't that many of us). So we expect to see a lot of variation based on hardware. As we learn about gotchas like this in the hardware, hopefully we can optimize at least some of them.[/quote]

anything somebody can do to help you with that? Deliver performance reports or what?

Anonymous said...

I am thinking of getting 8gb of ram in december. Just wanted to ask you if x-plane is capable of registering this amuont of ram? Yes, I know I need the 64-bit version of windows etc etc. But let's focus on x-plane.


Anonymous said...

The view should also change in the following pics:

You should be able to see more of the right part of the runway if you are sitting on the right part of the cockpit.

Benjamin Supnik said...

More follow-up:

1. Please DO NOT report bugs on this blog!!!!!! I cannot process bugs reliably here. Go to the x-plane contact page and use the bug report form.

2. 8 GB of RAM won't help. X-Plane is limited to 3 GB of RAM by the OS (even a 64-bit one) because it is a 32-bit app. Conceivably someday video drivers could use extra RAM but I suspect that for a while, 4 GB will be the most it pays to have (unless you are running another big app with x-plane).

3. We aren't quite ready to solicit hardware-performance infor yet, but we will be shortly. I'll post here or to the news group when we need specific actions - thanks for the offer.

Anonymous said...


just a hardware guide question.

Under what circumstances(in general) is a graphics card upgrade required ? What rendering elements are CPU or GPU intensive ?

Benjamin Supnik said...

See this for CPU vs. GPU

A GPU upgrade would only be required if you want to run the sim and you're below min system requirements.