Frame Rates...

[birdguy 3,943]

Does limiting the framerate to 20 or 30FPS improve performance?  Some people set the slider to 30 while others set it to max.  Why?  What advantage is there to limiting it?  And if there is none why have a slider at all?

Noel

[charliearon 3,017]

Have you tried it either way yet, Noel?

[John_Cillis 2,406]

59 minutes ago, birdguy said:

Does limiting the framerate to 20 or 30FPS improve performance?  Some people set the slider to 30 while others set it to max.  Why?  What advantage is there to limiting it?  And if there is none why have a slider at all?

Noel

In P3DV4.4 I limited my fps to 33.  Just chose the number.  Only reason I put the limit there is due to the load of photoscenery I have, there's a lot of work to do to load my MSE scenery.

[birdguy 3,943]

Yeah Charlie, I've tried it both ways.  I have a test flight I make whenever I want to make a change or add something new.  I fly from Montgomery Field in San Diego to Big Bear City Airport in the San Gabriel Mountains.  It gives me a variety of terrain to fly over and a challenging approach from the west threading the mountains at 8500 feet.

I notice no difference in performance one way or the other. 

Noel

[fs4fun 366]

2 hours ago, birdguy said:

Does limiting the framerate to 20 or 30FPS improve performance?  Some people set the slider to 30 while others set it to max.  Why?  What advantage is there to limiting it?  And if there is none why have a slider at all?

I believe the purpose it to try to maintain a consistent frame rate, rather than having the frame rate jump around which might be visually jarring. There tends to be spikes in the load during takeoff and just before landing but also at other seemingly random times the sim gets busy dealing with weather updates, scenery loading/unloading, rendering textures for newly visible LOD cells, tessellating mesh and so on. So one school of thought is to set the frame rate to some nominal value that leaves some headroom to allow for spikes in load so frame rate stutters are minimized.

Another thing is to consider your monitor's refresh rate. For example if FPS is higher than the refresh rate, then you would be wasting cycles rendering frames that will not be displayed. Also if your FPS rate and refresh rate is mismatched you could see some "tearing" of the screen image due to having parts of different frames appearing at the same time. People with 60Hz monitors sometimes set FPS to 30 to reduce tearing. There are newer standards like G-SYNC and FreeSync which adjust the monitor's refresh rate to the game's FPS rate automatically so then you don't need to worry about this issue.

I think of frame rate as the performance figure, so limiting the frame rate is constraining performance in a way, but doing so with the goal of a better overall result.

Edited February 8, 2019 by fs4fun

[Rogen 1,087]

In my experience the use of vsync is as a frame rate limiter, that also provides an incredible level of smoothness when both the output frame rate and monitor hz are in sync.

If your monitor refresh rate is @ 60hz  and vsync/unlimited frames are on then P3D will try and maintain a fps rate of 60, which in general can be difficult to maintain and tends to use a lot of resources.

However if your monitor refresh rate is 30hz then P3D will try and maintain a frame rate of 30 fps, and most machines can keep up with 30 fps and have a degree of overhead for those areas where there would be heavy frame rate drops.

With vsync on and unlimited frames you've set P3D to run as fast as it can but at the same time to keep the frame rate matching the monitor hz value i.e. 30 hz equals 30 frames per second.

So ideally a reasonably powerful computer and GFX card, (e.g I have a Ryzen 1700 O/C to 4.1 Ghz and a GTX1070Ti) will be able to maintain a 30+ fps frame rate and a monitor that can sync to 30hz will provide an excellent enviroment for syncing the frame rate to the refresh rate for silky smooth performance.

Occasionaly I jump into FSX-SE and I'm amazed at what I used to think was smooth is actually full of jumps, stutters, and is not smooth at all, as compared to P3D with vsync on, unlimited frames and a monitor refresh rate set to 30 hz.

Of course if a machine can actually maintain 60 fps, then a 60 hz refresh rate and vsync on will provide an even smoother level of performance, maybe in a few years I'll be able to afford such a machine, or maybe P3D performance will jump expotentially, who knows...

Here's a thread that discusses it a little further.

Cheers

 

Edited February 8, 2019 by Rogen

[vgbaron 3,486]

3 hours ago, birdguy said:

I notice no difference in performance one way or the other. 

Noel

Then you've answered your question.  

Depends on sysem - I lock at 20 and it's smooth as glass - others lock at different settings or unlimited.

Depends on CPU, GPU, Memory........

Vic

[stans 702]

There are a number of variables and sometimes explainable factors that affect performance with the frame rate limiter.  With my system, I have found that unlimited minimizes stutters, but increases blurries, while limiting frame rates to 20 or 30 eliminates blurries, but increases stutters, mostly when on the ground.  There is no harm in trying the frame rate limiter and you might find a setting that works really well.

[birdguy 3,943]

I guess I'll just leave it where it is.  Being a dummy when it comes to modern computers (I was a guru in DOS before windows came out) I tend not to mess with things if they work even if a tweak will make it work better.  I rely on others for advice.  I have no idea what vsync is or how to mess with refresh rates.

Noel

[Mace 1,901]

1 hour ago, birdguy said:

I guess I'll just leave it where it is.  Being a dummy when it comes to modern computers (I was a guru in DOS before windows came out) I tend not to mess with things if they work even if a tweak will make it work better.  I rely on others for advice.  I have no idea what vsync is or how to mess with refresh rates.

Noel

Don't you have blurries running unlimited?

What cpu do you have?   If it has hyperthreading, is it on or off?

[Rogen 1,087]

12 hours ago, birdguy said:

I guess I'll just leave it where it is.  Being a dummy when it comes to modern computers (I was a guru in DOS before windows came out) I tend not to mess with things if they work even if a tweak will make it work better.  I rely on others for advice.  I have no idea what vsync is or how to mess with refresh rates.

Noel

Mate, if you were a DOS guru then this stuff will be managable and it's GUI driven.

In Prepar3D vsync is a On/Off dropdown and a checkbox, you'll find it located as per the following in P4D v4.4.

• Prepar3D open
• Menu/Options/Graphics/Display/Frame Rate Controls

To see the Hz capabilites of the monitor, check with either windows itself or the Nvida Control Panel, note Windows(10) is a somewhat convoluted process compared to the NVidia control panel.

 

Windows (10):

• Right click on the desktop and choose Display Settings
• When the Display Settings window opens, locate and click the Advanced Display Settings link
• When the Advanced Display Settings windows opens, locate and the click the Display Adaptor Properties link
• Another Windows will open, choose the Monitor Tab
• The available Refresh Rate Hz will show in a drop down

Unfortunately Microsoft appears to be practicing delibrate obfusication/dumbing down with each new so called "better" version of Windows10 so things might be a little different the above, plus the "windows" (in Windows10) typically do not have the option to search the window contents like their previous releases did. And they also remove abilities and obfusicate for what was previously simple functions such as file associations and choosing a default program, but anyway, MS are clearly on an Emperors New Clothes type of path and that's that, and enough Windows ranting, I really hope Lockheed Martin have a plan in place to move off windows, even it it takes a number of years, maybe with a Vulcan engine perhaps ???

I think when I'm forced to move from Windows 7, I'll choose a LTSB edition of Windows10 (which has a locked feature set i.e. no massive twice yearly potentially breaking feature updates bringing more problems and less desirable so called features).

 

NVidia Control Panel:

• Open the NVidia Control Panel
• In the Left Hand Pane, navigate to Display/Change Resolution and select
• The available Refresh Rate Hz will show in a drop down to the right of the Resolution picker

 

For an average monitor the refresh rates will be 50/60 Hz with 60 the default, if you are luckly you'll have lower rates showing, which would typically mean you could probably configure a 30 Hz rate (see my previous posts in the thread) in the NVidia Control Panel for example.

As a test you might want to try setting the Monitor refresh rate to 50 Hz and enabling vsync/unlimited frames in P3D.

Such a setting means the frame rate will be locked at 50 fps (MAX) and while I've often found while 60 fps maybe unreachable, 10 fps less might be more achieveable, especially if flying photo real sceneries such as BlueSky/Mega

Cheers

 

Edited February 10, 2019 by Rogen

[birdguy 3,943]

Rhett, my CPU is an i7-7700 @ 4.2GHZ.  I have 64GB of RAM.  No I don't experience blurries.

I have no idea what hyperthreading is.

Rogen, I have Windows 10 which confuses me.  My system is working and all I really wanted to know was how framerates affect performance since I see no difference between locking it at 30FPS or running it wide open.  I just wanted to know which is better.

Noel

[Mace 1,901]

1 hour ago, birdguy said:

Rhett, my CPU is an i7-7700 @ 4.2GHZ.  I have 64GB of RAM.  No I don't experience blurries.

I have no idea what hyperthreading is.

Rogen, I have Windows 10 which confuses me.  My system is working and all I really wanted to know was how framerates affect performance since I see no difference between locking it at 30FPS or running it wide open.  I just wanted to know which is better.

Noel

Which is better, is whatever works for you, I'd say.  If you have smooth frames and no jerkiness, and you see no blurries, then keep it as you are.

Many systems can't run unlimited because that is telling the sim to put most cpu time into frame rate -- which leaves less cpu time for texture loading.   But if your machine can keep up with the texture loading and is smooth, keep at it I say.

Wow, you have a lot of ram Noel.  That's nice to have.

[birdguy 3,943]

Rhett, two summers ago I would purchase parts for a computer to build as I could afford them.  Everything but the case and the liquid cooling system.  By the end of the summer I had all the parts; motherboard, CPU, RAM and took them to my computer shop which a friend owns and he got the case, power supply and  cooling system and built it for me.

I got recommendations for the parts from my friends at the Orbx forum.

Noel 

[sloppysmusic 169]

My experience is with 4 cores or less lock the frame rate, with 8 cores use unlimited. The sim runs smooth on its core with plenty others to take the load for all the add-ons. Not finite advice just in my experience. Current cpu Intel i7-6900.