X-Plane 11 & Pimax 8KX performance teaser (optimal quality + ORBX scenery)

Hi guys!
Since a few days ago I’ve been messing around a lot with X-Plane 11 VR with the 8KX for some upcoming videos (including other VR flight sims). Just want to give you a hint about the performance here.

This time I have chosen to really take the time and find an optimal balance between image quality and acceptable performance. Im using ORBX scenery to really show the most GPU/CPU intense scenarios. ORBX TrueEarth US Northern California (around SF), ORBX LOWI Innsbruck, ORBX TrueEarth Washington and others. Basically as intense at it gets when it comes to scenery. World Objects is kept on Medium because everything above kills the CPU and lowers the framerate by 10-15fps or more. Remember, these sceneries are extreme when it comes to world objects, textures and mesh.

As you know, X-Plane11 tanks the CPU and GPU because of the bad optiomization, and there is no way to run this thing in a full 75fps frame rate. Either way, with lots of tweaking (Process Lasso, FlyWithLua NG, XP11SettingsTool, overclocking etc) a stable fps mostly above 40 its really not bad - and yeah it looks awesome! Running with Smart Smoothing enabled (37,5fps) makes the flights totally smooth as well, with very minor artefacts.

The settings Ive found looks best and still being “doable” are:
PiTool 1.0, SS 70-72% (due to Parallell Projection, resolution is set to as close to 3800pix horizontally as possible)
Visual Effects: Medium
Texture Quality: Maximum
Antialiasing: 4x
World Objects: Medium
Reflection: Minimal

I will first do a round-up of the performance in 6 or 7 flight simulators including X-Plane 11, and then in upcoming videos I will dig deeper into the settings and optimization.

Some good news is also Im testing a 60Hz firmware on the 8KX and so far it works perfectly. X-Plane in 60Hz and Smart Smoothing at 30fps runs smooth basically everywhere on my system. The minimal smart smoothing artifacts are identical in 60Hz/30fps as 75Hz/37,5fps.

No Smart Smoothing:


No Smart Smoothing:

No Smart Smoothing:

No Smart Smoothing:

Smart Smoothing ENABLED:

No Smart Smoothing:

No Smart Smoothing:

No Smart Smoothing:

No Smart Smoothing:

18 Likes

Oh, btw. Recording these clips takes away between 3-5fps also, so add that upon the numbers.

8 Likes

Nice work. This is how to test flight sims - run them through the most extreme scenarios in use to ensure stability.

FPSVR seems to be showing the same CPU spiking behavior I see in DCS World. Regardless, it seems CPU is the limiting factor, so if the behavior is similar to DCS World, it should be possible to push the GPU even more, to 1.5x Total SR.

This will make it much easier for me to get started on XPlane 11, comparing such things as Smart Smoothing, 60/75Hz.

In the meantime, I have added your settings to a draft page of my param spreadsheet, making a few assumptions for things that were not exactly specified (ie. vertical pixels were inferred from horizontal resolution assuming Normal FOV).

3 Likes

Are these through the lens images?

This is not about through-the-lens readability, it is about what objects are displayed in the scene, and what framerates are achievable under those conditions.

Now obviously not. And they are at much lower resolution than the headset, so things will be more readable.

2 Likes

@SweViver
Hey, very nice keep more of the Simulators coming.
Have you noticed rotational input lag on the 8KX on 60Hz, like the Pimax 5K+ SN204 suffers from on 65Hz? Does the entire world scene move slightly with you?

Please keep an eye out for that, it’s a problem that makes the 5K+ SN204 unusable at 65Hz, the software engineers must get the 8KX to work properly as the premium flagship.

2 Likes

@SweViver
JoCool is indeed referring to an actual bug at least with older PiTool/firmware versions. In the case of this NOT FINAL 8kX, I can only confirm this happens after VRAM exhaustion, and is solved by a reboot.

It is a minor inconvenience that has nothing to do with refresh rate, at least not with this 8kX.

4 Likes

FYI it is present in the most actual PiTool 254 and FW 255 for the 5K+ SN204.

Link to the bug report

It is not caused by VRAM exhaustion btw. My RTX2080ti is pretty beefy. It is a PiTool or Firmware bug, and can be reproduced 100% by selecting 65Hz, and immediately vanishes when switching to 90Hz or 120Hz. Any other variable (be it FOV, Steam branch, game, etc. is irrelevant to it).

It is important to me that such “early software issues” (cough cough) do not appear for the premium Vision 8KX.

Little rant:
Given the history of how inconsistent the Software updates have been, I may go as far to say that Pimax needs to hire additional Software Engineers / [edit] these who had been doctoring at it so far. I’ve had experienced a fair share of trouble with these bugged releases, unclean branching (yeah, I can tell), forgotten HMD versions, consecutively ignored problems, bugged FW patchers, that I would go so far that I’d open a bottle of champagne if those responsible for it would get [Edit: Assistance].

And I’m a big fan of Pimax’ devices btw. I recommend the headsets to people regularly.

3 Likes

‘at least not with this 8kX’

I suspect there are multiple ways to cause this bug, differing with headset type as well as software/firmware versions.

I think it might help Pimax to have a mechanical latency test jig of some sort.

1 Like

I suspect so as well. I’m glad this is only sometimes the case with the pre-release 8KX. I would expect it to be non-existent at all in the released 8KX. It was a big issue with the initial 8K release for quite a few people, and would be a catastrophe.

When flying Simulation for 3 hours, a reboot in between is impossible. :sweat_smile:

3 Likes

Which is a major reason my spreadsheets exist - to ensure whatever configuration is used at startup is well within safe margins!

3 Likes

Have you tried 2x or even disabling AA? With the extra resolution of an 8KX, I would think that 2x would be sufficient. That might boost your framerate a bit.

1 Like

I will investigate this today. Havent seen any issues yet, but I might have missed something.

The 254 version have issues indeed. Stability is the bigger problem I would say. Crashes/freezes randomly on high load.

I totally agree and Im discussing this.

Here is the thing. XPlane must be the most weird simulator of them all. There is just something that doesnt add up, compared to P3Dv4, Aerofly, DCS etc.
At default PiTool, full 3800 resolution, without AA its super jaggy. Framerate is maybe 20-30% better but then again the CPU is the main bottleneck here.
With AAx2 its better but still not good.
With AAx4 its fully doable but still not as good looking as Aerofly or even P3Dv4.
With AAx8 it looks great bit framerate suffers big time.

Using a higher resolution in PiTool, without any AA, especially PiTool 1.5 and leaving the SS at 100% makes it look very good but framerate is super low. Decreasing the SS near 3800pixels makes it look as bad as PiTool 1.0 with SS 100% or actually even worse.

This simulator just cant run on a higher resolution than 4K with more than 20fps. With 4K and AA at least its doable in 35-50fps. But its still the most jaggy simulator of them all.

It seems we cant to much more until 11.5 arrives with Vulkan. Ive spent way too much time on this sim and still haven’t found an optimal setting with OK framerate and an image quality that compares to AeroflyFS2 or P3Dv4.

4 Likes

Thanks for the response. Yes, I hope they can improve on that.

Ref XPlane: Some Simulators are limited by their pipeline. There’s only so much we can do.

We have similar issues with IL-2, which throttles mostly on one core, and runs on forward rendering while drawing quite a few lights and shadows. They are however steadily upgrading their engine, have added Pimax support (fantastic, no culling issues, no PP necessary!), even made transitions to new DirectX versions, are thinking about switching to deferred rendering, etc.

The point is, guys: Sometimes it’s in the hand of the developers to improve their product. Look at how IL-2 improved, how DCS improved since after its disastrous deferred rendering patch. XPlane needs steady input and improvement by its Devs. Performance and image quality can rise and fall depending on the games you play.
The 8KX will probably show the ugly ducklings, as its clear screens will show everything. Might even consider playing XPlane on upscaled mode, to see if jaggies get reduced and performance increased.

In the end, you’ll have a highly versatile headset for every situation.

5 Likes

The Vulkan update will bring a small improvement (for nVidia) according to the dev blogs from a while back. For AMD its a different matter - this is signficantly improved.

From memory, I think the AMD improvement was around 30-40% but for nVidia its <10% because nVidias OpenGL drivers are actually really efficient. (although any increase is welcome in VR)

However, they said that one of the goals is to make the simulator less prone to stutter as OpenGL will stall the pipeline when moving textures around, especially in graphics card low memory situations. In the longer run it will also allow them more flexibility in some of their other processing functions and presumably also allow them to find other performance improvements.

Edit: Found the video: https://youtu.be/Lrxkv2DSHAI?t=2551 (from around 42 minutes)
AMD 20-40% faster - Nvidia 5-20% faster… So still a good improvement

1 Like

I am not yet seeing stability/crashing issues with PiTool 254. I will continue to investigate why.

2 Likes

@Sweviver: great to see such scenery in VR - does Pimax reach out to Microsoft, or better Asobo Studio to see if they are really working on VR mode for the upcoming Flight Simulator 2020 and could use a Pimax headset to factor in while developing it - e.g. to have them take canted displays into account right away ? I expect FS2020 to be quite a success from the material which has been presented and from a glimpse I had at the alpha, so once that releases and adds VR support it would be great if it runs smoothly on Pimax headsets.

3 Likes

I have contacted them some time ago with a few questions. No response yet. But hopefully we will get something cooking. Meanwhile can at least hope the FlyInside team is working on something for the FS2020.

7 Likes

X-plane will be in big trouble when MSFS is out. MSFS excels in every aspect including FPS. Wait, not every aspect. There is still uncertainty if and when it will have VR. That’s really a shame. VR will make people crazy in MSFS. And 8KX is the best match for MSFS VR. Really wish both Pimax and MS/Asobo can use each other as a selling point. This is a win win situation.

3 Likes

Flight sims are all about how close to real flight it is. Aerofly has clean graphics and smooth frames and it’s feel of flying is comparable to playing with a toy car…it’s just not flying at all.
I have no doubt MSFS will be better flying than Aerofly but extremely doubt it will compare to FSX upon its release anyway.
I think they’ll chase FSX and even have a high probability of becoming as good, but several years after release.
They have a lot of history of pioneering the best home pc flight sim…but they sold it and I imagine they don’t still have access to the people who developed it…and have missed so many years of FSX and P3D clawing ahead in realism. It will take years to catch up. But I believe they will too.

1 Like