A little advice on Graphics in P3D

[AirCanada235 103]

Gents,

As an avid reader of many different forums, I am pasting below, something that I found on the FSLabs forum which I personally thought was an amazingly articulate piece on the correlation of graphics and your systems.  I take NO credit for this but again - wanted to share.  Enjoy  DR

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Much has been said about this over the months and years, but I’m going to add my few quid because I’ve had a huge degree of success with it. Therefore, perhaps some of you can benefit from my experience.

Firstly, simmers tend to be obsessed with frame rates, in the mistaken belief that higher frame rates are the key to a great flying experience. This is completely wrong. Frame rates are important in first person shooter games, where on the onscreen action is fast and furious and milliseconds are the difference between winning and losing.

What us simmers need (I’m a gamer as well by the way) is fluid and stable frame rates, without stutters at just high enough frame rates to deceive the eye into thinking it’s looking at motion. The illusion of continuous motion is only convincing (and therefore immersive) if it is smooth. Essentially we need 29-32 fps. Anything higher and you’re probably wasting capacity at the expense of something else.

Many people report having rates of 50-100 fps which, if completely stable is great. However, stuttering and fps instability even at these rates will still kill the illusion dead. It is worth mentioning that stutters may not show up as momentary drops in fps on the beloved red texted frame rate counter.

Don’t confuse stuttering with low frame rates. They are completely different issues and may be caused by completely differing reasons. People often associate stuttering with having low frame rates, and therefore believe that their attention should be focussed on increasing frame rates to cure the stutters. They are barking up the wrong tree. There are 2 main causes of stuttering:

1.       System bottlenecks – The throughput of data demanded by the sim overstretches the capacity of the system to provide it continuously. By system, I mean your entire setup, including your monitor.

2.       Syncing – Your monitor, graphics card and remaining system must all be perfectly synchronised. Like the gearbox in your car, if the components aren’t meshing in synchronicity, there will be grinding and lurching all around. This is a good metaphor because it demonstrates that smoothness is not dependant on speed or frequency. Smooth gear meshing will provide smooth transmission at any speeds from standstill to racing speeds.

It's pretty easy to isolate what is causing what. Simply put, system bottlenecks tend to produce random stutters which vary a lot in amplitude and follow no particular timing pattern. On the other hand, syncing stutters tend to have a more stable, rhythmic pattern to them, like one solid stutter every second, or half second. A good way to see this is to jump to the default spot view by pressing “S”, then panning continuously around your aircraft, looking down at about 20-30 degrees. After a few revolutions, you should be able to see if your stutters are stable or more random.

With this in mind, don’t be fooled into thinking that if you have massive throughput capacity, there won’t be any immersion killing stutters. If your monitor isn’t properly synchronised with the action, you’ll get massive, brain twisting stutters (which may lead you to believe you have a frame rate problem). Your output device (monitor) is like the tyres on our metaphorical car. If the engine and transmission are running beautifully smoothly but you have one or more misshapen tyres, the car will drive like word not allowed, regardless of power output and speed.

Once you’ve isolated the cause, you can fix the problem. You don’t need to mess around with Nvidia Inspector, Process Lasso, or any other stuff. You just need to understand the problem. I have used Process Lasso recently and believed that it was helping. However, when I found the real cause of my stuttering, I realised it was a placebo effect, so I got rid of it.

Firstly, you need to aim for a specific lower frame rate threshold that your system can maintain in all or nearly all scenarios. Ideally 30 fps. Any modern reasonably high powered machine can achieve this if you’re not too greedy with your settings and appreciate which things can be turned off without killing the immersion. I’m not going to go into exactly what my setting are because they are specific to my machine. The simple way to find out for yourself is to start with everything set to medium (including anti-aliasing etc) then pick a scenario which represents a reasonably challenging scenario for your system. Save the scenario, then gradually increase settings, incrementally, one at a time until your lowest frame rate hits 30.

This is only half the story though. You MUST then ensure that your monitor is synced properly with the system output. I use a 40” TV as my monitor. It runs at a native 1920x1080p resolution at a refresh rate of 60Hz. By the way, TV’s don’t make great monitors for a number of reasons, but it’s what I’ve got.

If my system could run everything with a lowest frame rate of 60fps, I’d want to make sure that my Vsync was outputting exactly 60 fps @ 60 Hz. However, my system can’t do that so… I have to improvise. The monitor refresh rate specified in the driver setting of your graphics card will tell P3D’s Vsync module what frequency to output at. This is absolutely essential for smooth graphics.

IF I tell my graphics card to refresh my monitor(TV) at the rate of 30Hz (or put another way, 30 times a second) then I enable Vsync in the P3D settings, the graphics driver will tell P3D’s Vsync to output at exactly 30 frames per second too. This results in perfect timing and therefore synchronisation between the system and the visual output. This further results in completely smooth, stutter-free fluid graphics. If you can make this work, it’ll feel like you think it feels at 40fps, 80fps and so on.

In summary –

Great flight simming is about creating the illusion of fluid movement. This gives you the feeling of momentum, movement, mass etc. Convincing Immersion is only possible with smoothness.

Forget high frame rates – they are irrelevant in flight sims above 30fps. You need to achieve 30fps as the lowest performance benchmark, then force the sim to stay there using Vsync.

Ensure that your monitor or TV is playing ball by forcing its refresh rate down to 30Hz. You won’t notice the difference in the sim, though you probably will at the desktop. Just enable it before you load your sim, then put it back to 60Hz when you’ve finished flying.

Then, just make sure that nothing in your other settings is causing momentary bottlenecks which cause the stable frame rate capacity to drop below 30fps. As said previously, you can do this by lowering your AA settings if required. AA and DL seem to have the biggest impact in the P3D V4, so it’s fairly easy to isolate them.

There is no need for complicated tweaks in Nvidia Inspector, third party apps, various driver versions, as it can all be done with your basic driver control panel and within P3D’s graphics settings. If you’re more inclined, you can use HWMonitor to see how your hardware is bearing up but even then, you only need to know your CPU utilisation and your GPU utilisation. Nothing else will really help you. That said, my overall CPU package is often running at or near 100% but I have NO STUTTERS. CPU maxing doesn’t always mean stuttering. It may just mean that it’s working hard, as you’d expect! GPU maxing is more likely to cause stutters and ideally you’ll have yours running at around 80-90%. Again, aliasing effects are often the biggest influence here, so adjust them accordingly.

Using this basic and logical approach, and understanding the problem, I have managed to achieve the following with my hardware and software setup:

Hardware:

Intel 7700K running at 4.0 GHz – I do not believe in overclocking. It just stresses your hardware enormously for very little real gain. Particularly as I’m not chasing ever higher frame rates.

Nvidia 1080GTX, Asus Maximus Hero VIII, 16 Gb ram running at PC2100, SSD for OS and P3D, Samsung 40” LED Monitor @30Hz for sims and 60Hz for desktop. Currently using driver version 388.0 but it doesn’t really matter which you use. I have only changed 2 things in the driver control panel – prefer maximum performance to prevent GPU throttling by reducing power, and monitor refresh rate @ 30Hz.

With this, I have Vsync turned on, frames unlimited, triple buffering on or off as it doesn’t make any difference for me, SSAAx8 during daytime and MSAAx8 at night time, with DL turned on.

DL does not play well with SSAA, so I use MSAA at night. In the dark, the difference visually is very small.

Using Orbx Global, LOWI, UK, Scotland, Wales, UK2000 major airports in the UK and a combination of Orbx, Aerosoft, Flytampa, Flightbeam, and FSDT for the others. I also use GSX.

On a networked laptop I have ASP4, ASCA and Avliasoft EFB. I occasionally use PTA with various pre-sets but often find that where they improve in some areas, they ruin in others, I often revert to default shaders which are fine. I run tex resolution at high not extreme because it’s pointless at a screen resolution of 1920x1080 and makes no visual difference.

With the FSL A320 in P3d V4, I can achieve completely smooth fluid graphics, at night, at LOWI, with DL on at 30fps. The same during the daytime with SSAAx8 and it looks stunning and feels stunning. All other P3D’s settings range from extreme to normal.

Stop chasing frame rates and concentrate on smoothness by improving your system’s synchronization.

[Rickie Welsh 27]

Hello Dave,  I read your post with interest but out of curiosity which Windows and Flight Sim are you using as I could not see them mentioned. Regards.

[downscc 1,327]

On the other hand, I get excellent results with frame rate locked at 24 and no VSync or buffering, 4xMSAA, 4K TV running at 60Hz.  Sure, I have played with VSync and buffering and 30Hz refresh but nothing improved the already excellent and smooth animation I am getting. I also believe in overclocking and it has nothing to do with frame rate.  I do agree that NI is no longer required and I agree that chasing frame rates is irrational; however, system settings will vary from system to system so there is no such thing as the best way for all.

[AirCanada235 103]

More meant and general info Dan

[vp49p3 216]

I have found the advice from this video invaluable in setting up not only P3D, but all of the common addons, such as AS4, Orbx, etc.  Sure helped me out to maximize the experience with minimal hit to performance

 

[chapstick 2,757]

So weird that he tells people not to overclock, especially when he has a processor designed for it. 

 

Alex Pugh

[Mikelab6 89]

The magic bullet here is the monitor refresh rate at 30hz. Mine is running at 60 hz only, so FPS is important for me to be higher than 60 to have a smooth experience.

Mike

[Boomer 1,619]

Hmm, the usual YMMV.

[vp49p3 216]

40 minutes ago, Mikelab6 said:

The magic bullet here is the monitor refresh rate at 30hz. Mine is running at 60 hz only, so FPS is important for me to be higher than 60 to have a smooth experience.

Mike

Mike--if you're using Nvidia inspector, try one half refresh rate. It mimics 30hz with my 60hz monitors, so at 30fps the sim's smooth.

Jay

[Chock 17,769]

2 hours ago, Boomer said:

Hmm, the usual YMMV.

Exactly.

Whilst there are a lot of valid points made on many tweaking and performance posts, there's always a lot of assumption too, and much of that is system specific as well, not least in imagining that everyone has an Nvidia GPU in the same way that there's often an assumption everyone has an Intel CPU, which they of course don't, so any stuff about what you need to do with Nvidia Inspector or some other hardware-specific tweaking aid is often irrelevant to many users. It's also regularly bandied about that this or that frame rate is the one necessary to create the illusion of movement, with many people quoting 30 FPS without really understanding where they've plucked that figure from. So I'm gonna put people straight on that one...

30 FPS was chosen for TV not because it is necessary to have that frame rate to create the illusion of movement, but because of the alternating current frequency in the United States, which is 60Hz. In the early days of TV development, engineers involved in creating the systems for TV broadcast needed a timing circuit in order to have video play back at a suitable rate for transmission, and since it was before the days of microchips and all that stuff, they had to use the electronics available at the time to regulate the timing, so they used a frequency which was readily available, which was the divisible half that of the alternating current, i.e. 30Hz, aka 30 image frames per second. But, in Europe the alternating current runs at 50Hz, so the frame rate used for TV in Europe in those early days was 25 frames per second. Most movie cameras on the other hand shot at 24 frames per second. So straight away you can see that 30 FPS wasn't necessary for a convincing moving picture.

30 FPS worked well until the desire for colour television came to the forefront. Most people imagine that colour TV is something which was only made possible in the 1960s and 1970s, but that's not true at all, colour TV was actually first demonstrated in the mid 1920s and as a theory it had been around since the latter part of the 19th century. However, early attempts relied on too many mechanical timing components to be of truly practical application and so it wasn't until near the end of WW2 when it became more feasible; technological advancement spurred on by the war having moved us on quite a bit electronically. This ultimately led to the NTSC standard for TV in the US in the early 50s, and the PAL system in Europe in the early 60s. However, colour TV didn't really take off in either Europe or the US until the 1970s, and when it did, this necessitated another change to FPS...

Upon colour TV being developed, both 30 FPS in the US and 25 FPS in Europe were problematic technically; when the additional colour signal was added to TV transmissions, it was so close to the signal for the sound that the image signal was phasing with the audio signal and creating moire patterns in the images which made the pictures look terrible. So in order to separate the audio and video signals when they were so close in the radio spectrum, the solution was to alter the video frame rate, but they didn't want to alter it too much since, as noted, the frame rate was closely tied to the frequency of the alternating current to facilitate timing and broadcasting the signal, so they dropped the frame rate by .03 FPS, which was the minimum practical amount of change to put the two signals out of phase with one another so the image looked clear. Thus the TV frame rate became 29.970 FPS, some other systems use 23.98 FPS, which is the universally accepted standard film gate speed of 24 FPS slowed down by 99.99 percent so that it can be more easily transmitted on the NTSC standard.

There is also some difference in frame rates when using either an interlaced or a progressive system, but you get the gist of it, which is that when people say 30 FPS is the minimum frame rate you need for a smooth illusion of movement, they are basically talking through their @rse, and simply repeating what they've heard about what the frame rate of TV is without understanding why that frame rate was adopted. The fact is, you can drop down to 15 frames per second and still have a reasonably convincing impression of movement, and this is quite often done in animation. You can even see this on some of your add-on aircraft in your flight sim, for example, the PMDG 747-400's Primary Flight Displays in the VC default to a 15 FPS refresh rate, and nobody complains about those looking jerky.

It is certainly true that a faster frame rate can help to make things look smoother, but the notion of 30 FPS being the minimum necessary for the illusion of movement is nonsense, because pretty much every movie you've ever seen, with the possible exception of some more recent ones shot at higher frame rates to facilitate post production slow motion effects, are all at 24 frames per second, and if you've ever watched any of them on TV, they are even slower, being at 23.98 FPS, which is of course more than 6 FPS below that 30 FPS number so many people bang on about as being necessary.

Most of the time, and as the OP article pointed out, it's consistent frames which matter, and the number is irrelevant so long as it looks smooth to you, which it absolutely will at anything around the 20-odd FPS mark.

 

[Mikelab6 89]

13 hours ago, vp49p3 said:

Mike--if you're using Nvidia inspector, try one half refresh rate. It mimics 30hz with my 60hz monitors, so at 30fps the sim's smooth.

Jay

Thanks, for FSX it's works because it's a true full screen mode, but half refresh rate doesn't works if your are not in full screen, and I am running P3D.  P3D is not a true full screen mode, it's a windowed mode without borders.

[mtrainer 136]

Might also add in that our movie theaters, with 24 FPS only, the films have also had undergone a "motion blur" effect during post processing for any fast moving items in scene.

Perhaps once video cards introduce this effect in hardware, we won't find our selves talking about FPS so much.

A high FSP sure makes for some nice landings though.  I go through a never ending cycle of slowly inching all the sliders up over a period of time, and then snap in utter frustration and dial it all way back down and whola!   I'm happy again.

Thanks

Mark Trainer