What number am I really seeing then when I see 160?  What does that actually mean?

 

Ed is spot on.

 

You are seeing what the video card is outputting to the monitor, however your monitor is only displaying based on it's refresh rate.

 

Hz is a way of saying "per second" when measuring a frequency, thus a monitor with a refresh rate of 60Hz displays 60 frames per second, and will never display anything higher unless the monitor is overclocked via a utility such as the NVidia Control Panel (whereupon most monitors fail to work)

There is actually a "Definable" smooth ... I've gone over the calculations before.  It's based around pixels per unit of measure ... assuming one is running 7cm texture resolution with 1m mesh resolution (1.19 meters per pixel).

 

I'll bring this article back from 2006: http://www.microsoft.com/Products/Games/FSInsider/developers/Pages/GlobalTerrain.aspx -- really good read and I highly encourage folks read it ... and if Jason Dent and Jason Waskey are still around for comment I would love to hear what they have to say.

 

But to make a very long story short, if you fly at 500 GS at 500' AGL and pan directly 90 degrees from forward motion view you would need to be able to sustain about 240 FPS (assuming you had a monitor that could operate at 240 Hz).  At 1000 GS, you need 480 FPS ... this is what I consider pure "smooth" ... meaning there is a direct 1:1 relationship between pixel motion and frame rates such that I would NEVER see a single pixel move more than one coordinate position up/down/left/right per single frame.

 

Obviously PC's are still a few years away at being able to do this with visually pleasing graphics.  So with this said, what I would recommend when attacking the problem of perceived stutters:

 

1.  Turn ALL the graphics to absolute minimum and disable all and any add-ons and make sure your DLL.XML and EXE.XML entries are all disabled

2.  Set Vsync ON

3.  Go fly

 

If you see stutters then there is something about P3D and your environment that isn't working well ... investigating this will be difficult but not impossible:

 

a. delete the P3D shader cache 

b. Remove and reinstall video drivers using the latest DDU tool (requires Safe mode)

c. Check your motherboard "shared" IRQ PCIe slot list ... sometimes moving a GPU to a NON-shared PCIe.X16 slot can solve it

d. Overclocking may cause error correction and/or VRM throttling issues if too hot

e. Check your monitor, how is it connected (HDMI - check cable is rated a necessary bandwidth, DVI-D with quality DVI-D cable - never use DVI-I ports and/or DVI-I cables at the back of the GPU)

 

If you don't experience stutters after turning ALL settings down and disabled all add-on (good news), then start the long process of turning back up graphics settings 1 at a time.

 

i.  Turn graphics setting back up ONE notch at a time and test

ii.  If graphics settings are at a nice level and all still stutter freeish, then start to enable add-ons one at a time and test

iii.  If a specific add-on triggers the stutters, then see if it has a configuration panel and adjust those setting to see if you can eliminate stutters

 

 If you want to be very scientific about the process, run FRAPS time frame logging as it will be easy to see how each setting is impacting the consistency of time between frames.  Time between frames is a key part of defining "smooth".

 

Cheers, Rob

Thanks all for your replies..It seems we agree :

 

Smooth flight is:

 

1) subjective to the observer's eye

2) when you can taxi, takeoff, roll, use TIR without any stutter 

3) when you look on the sidewindow during takeoff without stutters

4) we can all experience this ''smooth'' flight as a base, when flying in clear skies over the pacific on a C172.

 

Bob, thank you for the information, however I think we should distinguish stutters from motion blur.

 

Stutters is when motion is stopped and restarted in milliseconds.

Motion blur is when your monitor cannot reproduce pixel by pixel the movement of an object because of the refresh rate limitation.

 

Motion blur is not killing the simulation experience. I can takeoff and and see the runway lights from my side window painting small lines as I accelerate, but the motion is fluid.

Another example: You can record a video of 300fps and watch it on a 60Hz monitor. The result will not be unrealistic. It will be totally smooth. That's because our eyes cannot distinguish that difference as motion blur. Our brains are programmed to see a maximum fps. I'm not going to discuss how much is it, because I should do an in depth research before I can say a number, but the point is that we cannot perceive an fps higher than the one we are capable of. If there wasn't that limit, you would be seeing the monitor in front of you going on and off 60 times a second (assuming you are using a 60Hz monitor).

 

 Stutters stop and restart my aircraft's movement, completely killing the feeling of flying in the fluid air medium.

 

So, I continue to believe that this is the number 1 priority of our community. We all love flying and if we want to do it as real as possible, this is the top ''add-on'' of our hobby. The ''fluidity'' add-on. We should feel the aircraft is actually flying. And of course this is half work of the add-on aircraft's flight's dynamic model.

What number am I really seeing then when I see 160?  What does that actually mean?

It means the sim is creating 160 images per second... but no matter what, your LCD display will never, ever display more images than it's refresh rate.

 

LCDs don't exhibit motion blur, it's not really possible. Any motion blur one might see on an LCD would be intentionally designed into the graphics engine being used to render a scene.

 

Rob's post is an excellent explanation as to why there are what many call stutters when one looks perpendicular to the direction of travel.

Rob's post is an excellent explanation as to why there are what many call stutters when one looks perpendicular to the direction of travel.

 

So, you say that our eyes can detect more than 30fps when looking perpendicular to the direction of travel? 

 

Also regarding motion blur, I can definitely say that during night landings when looking at the replay from the passenger view, I have seen the runway threshold lights painting small lines in the monitor...so, how that is called?

Feels like people have forgotten what simming is all about.... I have a hugely powerful rig, I get smooth mostly but occasionally I get stutters and hiccups. I just don't care anymore, I have a great time 'FLYING' MY SIM doing landings, take offs, buzzing about, long distance flights... and giving up the constant tweaking.

 

We're dealing with ancient code that has been taped together time and time again. LM has done a good job of actually trying to work on this Frankenstein.

 

Learn to stop worrying and just love the bomb.

 

(DISCLAIMER - MY OPINION ONLY)

LCDs don't exhibit motion blur, it's not really possible. Any motion blur one might see on an LCD would be intentionally designed into the graphics engine being used to render a scene.

 

 

They would depending on their pixel response time.... if the pixels are not updating fast enough you will see some blur. The same way you see the ball dragging across a screen when watching football or tennis on older LCD type monitors. 

You'll have to excuse me, I've not read all of the posts in this thread, but in response to the question of achieving smooth gameplay, for me the equations looks like this :-

 

If <TrackIR=no>, then (FPS=>23) = smooth

 

If <TrackIR=yes>, then (FPS=>27) = smooth

 

simples! :smile:

It means the sim is creating 160 images per second... but no matter what, your LCD display will never, ever display more images than it's refresh rate.

 

LCDs don't exhibit motion blur, it's not really possible. Any motion blur one might see on an LCD would be intentionally designed into the graphics engine being used to render a scene.

 

Rob's post is an excellent explanation as to why there are what many call stutters when one looks perpendicular to the direction of travel.

 

Actually all LCDs exhibit motion blur, or more specifically slow pixel response times. For example in a dark nighttime scene, a group of pixels display white (like in landing light for instance) that turn black/dark when they are now display the ground, sky, whatever, take a few milliseconds to switch from white to black. In effect this creates motion blur, or really more of a "motion trail." When you're looking at monitor specs, you'll often see grey-to-grey or "G2G" response times. This is a measurement of the time it takes for pixels to change, effectively a measurement of how much motion blur there will be.

 

Check out www.blurbusters.com some time if you're bored, lots and lots of info on this topic

My LCD monitors have a 5ms response time... that's 200hz. The screen still is limited to a 60hz display cycle. I'm fairly certain that timing wise... there's no motion blur.

For me it would be probably an experience where I can pan around with no detents. So there are instances where I get a loading pause like FSDT JFK and other high quality airports and I honestly can live with that. But what I cant live with is being on a 10NM final and any control inputs are delayed because the sim is paused due to rendering a scenery or the kind of stutters I get with SGSS on Nvidia Inspector over an area with heavy cloud coverage. That for me is an experience killer. But a smooth flight with my VC descending through an overcast layer and turning smoothly white is a what I call ice skating experience.

 

Ice Skating=Momentary loading pauses due to Hard Drive speed but still smooth enough that I cannot control my aircraft due to stutters from the CPU or the GPU.

 

Regards!

My LCD monitors have a 5ms response time... that's 200hz. The screen still is limited to a 60hz display cycle. I'm fairly certain that timing wise... there's no motion blur.

 

I won't argue the point with you anymore, just say to look at at http://www.blurbusters.com and you'll see images of how LCDs produce motion blur. My Asus ROG Swift has 1ms GTG and still produces motion blur, even at 144hz.

I have seen the runway threshold lights painting small lines in the monitor...so, how that is called?

 

That's a monitor problem ... usually indicate of poor pixel clock.  Unfortunately many folks don't look at or understand the specifications of a monitor and/or why one monitor cost less than another monitor ... many (not all) tend to just look at what a monitors refresh rate as the "defining" part about a monitor - it's really only one small aspect of that monitor.  Combined with a mix and match of "standards" it's often hard to figure exactly how capable a monitor is.  This is why I tend to buy my monitors from retail outlet so I can return them if I'm not satisfied with the image quality.

 

P3D doesn't emulate motion blur (thank goodness) ... because I never really understood this entire "motion blur" non-sense many 3D shooters introduce, when I rapidly move my head I'm not seeing blur, nor when I'm racing, it's all clear no blur  (phew!)

 

Can people detect more than 60 FPS? IMHO opinion yes they can because the brain doesn't operate on FPS (the brain fills in much of what it doesn't see) ... but there is a real problem of bandwidth now ... HDMI 2.0 caps out at 18Gbps (that's A LOT of data) with 4K @ 60Hz ... I'm not aware of any specification that would support 4K @ 120Hz using 4:4:4.  The only way to accomplish that would be the old divide and conquer approach (multiple devices output multiple streams with dedicate cable/port for each stream feeding separate panel divisions). 

 

DisplayPort 1.3 can support about 26Gbps but that's still not enough for 8K @ 60Hz and certainly not enough for 4K @ 120Hz ... unless you drop to 4:2:0 which is not desirable.

 

A good example of where FPS becomes significant are racing simulations ... back in the days I used to do iRacing as training ... I was clearly faster and more consistent when I operated at 120Hz vs. 60Hz.  There was just that much more "resolution" (not pixel, but input resolution) such I could hit my marks more accurately and more consistently each time (and in iRacing I'd have no problem sustaining 200+ fps).

 

But my point in this was:

 

1.  There is a finite calculation of what "absolute" smooth is (regardless of eye/brain perception)

2.  Time between frames and how consistent that is will be the key to a relatively "smooth" flight simulation experience

 

 

 

We're dealing with ancient code that has been taped together time and time again. LM has done a good job of actually trying to work on this Frankenstein.

 

The code maybe oldish and there maybe lots of hacks in it to support backwards compatibility, but the basic Quad-tree design (see the link I posted earlier) is solid and is being used today in XP10, FSX, P3D, and even Outtera  (not sure about DCS but would guess there too).  But just so you know, older code is often faster because it didn't have the luxury of today's hardware (so optimization was key to its development) ... the only advantage to compiling with new development tools (i.e. VS 2013/2015) is so the applications can leverage newer instruction sets from Intel/AMD.  P3D is compiled with VS 2012 (and maybe now with VS 2013) so it'll gain some optimization benefits there.

 

So the "how smooth is smooth" ... my answer is how good are you at filling in the blanks?     Maybe in few years we don't have to, fingers crossed.

 

Cheers, Rob.

 

 

True, LCDs were a huge step backwards in terms of smoothness and image quality as it relates to motion.

 

And night flying looks so much worse on LCD, my old 21" crt was pitch black at night and the panels looked great, these days it looks like 8bit on an LCD