The importance of Framerate/FPS in racing

[Captain Chaos]

The following is undeniable and are facts when it comes to racing games. Developers of sub par games want to brainwash everyone into thinking all of a sudden 30fps is at all acceptable in this day and age.

Source: http://members.iracing.com/jforum/posts/list/25/1828482.page#4013122

this is taken from the professionals at iRacing the worlds most advance racing simulation.


TLDR=At 100 miles per hour, you're traveling about 147 feet per second; at 70 fps, you're traveling 2.1 feet per every frame rendered.

Kick that up to 140 miles per hour and you're traveling about 205 feet per second; at 70 fps, you're traveling almost 3 feet per every frame rendered.

On a road course, coming down a long straight to a corner where you have to brake, hitting your marks and braking at the right point is critical -- if you're braking down from 140 miles per hour and you're only getting 70 fps, the difference of one frame could mean braking 3 feet too early or 3 feet too late. The eye may not be able to detect this, and you will always anticipate your reaction to some degree but with higher framerates you come closer to actually seeing in real-time, so there will be less need for anticipation.

I think anything less than 84 fps (the default framerate cap) is insufficient, and everyone's goal should be to NEVER have their framerate drop below that point.

You also don't want your framerate fluctuating -- if you're getting 150 fps most of the time, but it occasionally drops to 120 fps, you WILL notice that 30 fps dip, so you're better off capping your framerate at 120 and just enjoying constant, fluid framerates.




FULL STORY!

Why is framerate important, and how many FPS do you need?

The commonly-accepted myth is that the human eye can't detect framerates over 24 fps, so using that "fact," a lot of people think that getting 35 - 55 fps in iRacing is perfectly sufficient, but I say it's not.

What it all comes down to is how you look at several questions -- for example:

How many frames per second can the human eye see?

This is a tricky question. And much confusion about it is related to the fact, that this question is NOT the same as:

How many frames per second do I have to have to make motions look fluid?

And it's not the same as

How many frames per second makes the movie stop flickering?

And it's not the same as

What is the shortest frame a human eye would notice?

If you'd like to dig into some of these questions, you can find more here (which is where I grabbed these questions from):

http://www.100fps.com/how_many_frames_can_humans_see.htm

Framerates (FPS) and iRacing

If you just want to know about framerates in iRacing, then read on -- or come back here after you click through the link above.

For me, my computer can crank out 200+ fps on a single screen setup in iRacing; if I lock my framerate at 60 fps, I have a harder time running close to my own personal best lap times than when I've got my framerate running above 90 fps

When it comes to framerate in something like iRacing, what you're concerned about is keeping up with the "physical" aspects of the game.

At 100 miles per hour, you're traveling about 147 feet per second; at 70 fps, you're traveling 2.1 feet per every frame rendered.

Kick that up to 140 miles per hour and you're traveling about 205 feet per second; at 70 fps, you're traveling almost 3 feet per every frame rendered.

On a road course, coming down a long straight to a corner where you have to brake, hitting your marks and braking at the right point is critical -- if you're braking down from 140 miles per hour and you're only getting 70 fps, the difference of one frame could mean braking 3 feet too early or 3 feet too late. The eye may not be able to detect this, and you will always anticipate your reaction to some degree but with higher framerates you come closer to actually seeing in real-time, so there will be less need for anticipation.

I think anything less than 84 fps (the default framerate cap) is insufficient, and everyone's goal should be to NEVER have their framerate drop below that point.

You also don't want your framerate fluctuating -- if you're getting 150 fps most of the time, but it occasionally drops to 120 fps, you WILL notice that 30 fps dip, so you're better off capping your framerate at 120 and just enjoying constant, fluid framerates.

I've got my framerate capped at 95 fps, and I never see my framerates fluctuate at all. More would be better, but for me 95 fps is a good compromise because I'm running two monitors, and if I go any higher, I start to see framerate fluctuations.

The benefits of capping your framerate

Being able to cap your framerate allows you to set a cap closer to what you see as your MINIMUM framerate. If your framerate is able to remain constant at 60 fps or higher (like around 84 fps, for example), then you're going to get the smoothest experience possible (the higher the better, of course).

The problem with no limit, though, is that by yourself or on desolate parts of the track (think back stretch at Laguna Seca) you might get an awesome framerate -- say, maybe 120 or higher -- but when a lot of cars are around, with dust getting kicked-up, in an area where there are lots of trackside objects and shadows (think anyplace near the pit area at most tracks), if your framerate drops significantly, you WILL notice it, and that framerate CHANGE may affect things like input lag and such.

If this "dip" in framerate occurs during crowded/tight conditions, it may happen when you NEED the most fluid, stable framerate in order to be able to respond properly, so a framerate fluctuation at the WRONG time may cause you to blow your race.

If your framerate drops from 120 down to 105, that's something you might notice -- if it drops from 120 down to 80 or lower, you WILL notice it, and if your max and min framerate is even greater than that, then you need to consider capping your framerate close to your minimum framerate (NOT the average).

On my system, I see anywhere from 135 to 165 fps as my max framerates, but it can dip down below 100, and that leads to problems during race conditions, so I've capped my framerate at 95 fps just to ensure that I never see anything below 95 fps, and I never see anything above 95 fps -- in other words, my framerate is always the same, and it's always equally smooth and fluid, with no "hitches" or variation, regardless of the race conditions.

That makes for the best overall experience, and it also means that I'm never going to see a framerate "hiccup" at the worst possible moment, when there's a lot of tight traffic and scenery, with a lot of dust being kicked-up.

Hope that makes more sense.

What does the "Cap frame queue" checkbox do?

From Build 2009.10.26.01 Release Notes

- new option added, “Cap frame queue”, which tells the sim not to queue up more than 1 frame at a time for rendering to reduce latency. Defaults to on (which is our usual behavior). Turning this option off may increase controller lag.

iRacing staffer Shawn Nash provided this additional detail regarding the "Cap frame queue" option:



Shawn Nash wrote:
The cap frame queue prevents several frames from piling up in a queue waiting to be rendered by the GPU. So it reduces controller lag. It uses frame queries to keep track of how many frames are currently in the queue. It is like the max pre-rendered frames in the nvidia control panel settings.

I've not investigated this option previously, but I think it's worth looking into more closely -- I'm not even sure what I've got this set to currently, but I am going to check to see if there is any noticeable difference with controller input lag on my system. Based on iRacing's release notes, I'd recommend keeping this checked, just in case.

More detailed and scientific information on frame rates and perception of motion:

Matthew Picken posted this in a separate thread, and it seemed like it should be included here in this discussion (thanks to Matthew for sharing):



Matthew Picken wrote:
Found this in Google Books:

Handbook of Driving Simulation for Engineering, Medicine, and Psychology.
Fisher, D.L., Rizzo, M., Caird, Jeff K., and Lee, John D. (eds.) (2011).Boca Raton, FL: CRC Press/Taylor & Francis.


On page 8-5, "perception of motion declines when the presentation rate of individual frames is slower than one every 40 miliseconds." This translates to 25 fps.

"The variation of smoothness of motion is often perceived as variation in velocity that is not simulated in the driving scenario but is an artifact of the variation in frame rate. This change in (perceived) velocity can have a profound effect on driving performance in the simulator."

On page 34-3, "for optimal perfomance and mitigating simulator sickness, a frame rate of 30-60 fps is considered minimal, and faster frame rates are desirable. Frame rates of 20 fps or less are noticeable to most people and the choppy image that results can be uncomfortable."

Based on the complexity of this book in the few excerpts that I read, the answer may well be anything above 60 fps that looks good to the user. Those excerpts came out of Chapter 8, Sensory and Perceptual Factors in the Design of Driving Simulation Displays. Not your everyday light reading.

Source: http://members.iracing.com/jforum/posts/list/25/1828482.page#4013122

[Tinki]

This is very instructive. But for these reasons I don't think this game is designed for competitive players or core racing gamers.

[YeOldeMurloc]

tl;dr

[SomePlayer]

Very thanks for the post.

[Fink]

Interesting write up.

However, people literally won't see anything above 60 fps on a 60Hz monitor from what I understand.

[Jin]

Publicado originalmente por Fink:

Interesting write up.

However, people literally won't see anything above 60 fps on a 60Hz monitor from what I understand.

60hz shouldnt be standard now days. Most gamers I know use 120hz or 144hz. Once someone who has tried 120hz, hes never going back!

Only people who still use 60hz for gaming are ppl who enjoy IPS for movie, or... ppl who cant affort it. Tho 120hz are quite cheap now, I cant see why anyone couldnt affort it.

[Xeno Metora]

k

[Fink]

Publicado originalmente por Invoky:

Publicado originalmente por Fink:

Interesting write up.

However, people literally won't see anything above 60 fps on a 60Hz monitor from what I understand.

60hz shouldnt be standard now days. Most gamers I know use 120hz or 144hz. Once someone who has tried 120hz, hes never going back!

Only people who still use 60hz for gaming are ppl who enjoy IPS for movie, or... ppl who cant affort it. Tho 120hz are quite cheap now, I cant see why anyone couldnt affort it.

Meh, I was just pointing out that you can't see anything above 60 fps on a 60hz since I didn't see it mentioned in the write up and could very well mislead someone who doesn't understand these things.

Fairly certain 120hz isn't anywhere near being the standard just by looking at newegg.

268 models for sale @ 60hz
10 models for sale @ 144hz
70 models total for sale above 60hz

[Jin]

Publicado originalmente por Fink:

Meh, I was just pointing out that you can't see anything above 60 fps on a 60hz since I didn't see it mentioned in the write up and could very well mislead someone who doesn't understand these things.

Fairly certain 120hz isn't anywhere near being the standard just by looking at newegg.

268 models for sale @ 60hz
10 models for sale @ 144hz
70 models total for sale above 60hz

If you are going to bring up statistic to back you up, at least be more specific...

What are the sale for each type of LCD? 60hz vs 120hz vs 144hz
What are the age of buyers?
How many buyers are using LCD for gaming?
... etc

I am not sure why you are arguing with me. Even if you dont think 120hz is standard. It is a fact that 120hz > 60hz on gaming and there are ALOT of people owning them. By capping FPS at 60, not only it handicap the high end hardware, it will also make the gameplay choppy. That should be the point of this thread no?

[Fink]

Publicado originalmente por Invoky:

If you are going to bring up statistic to back you up, at least be more specific...

What are the sale for each type of LCD? 60hz vs 120hz vs 144hz
What are the age of buyers?
How many buyers are using LCD for gaming?
... etc

I am not sure why you are arguing with me. Even if you dont think 120hz is standard. It is a fact that 120hz > 60hz on gaming and there are ALOT of people owning them. By capping FPS at 60, not only it handicap the high end hardware, it will also make the gameplay choppy. That should be the point of this thread no?

I honestly couldn't be arsed to be more specific. Perhaps it is the new standard, but if your only evidence that it's the new standard is that it's gudder, I personally am not believing it.

I didn't know that was the point in the thread, mind you I skipped alot of it since I already knew much of what was being said. I personally thought the point was to explain that higher framerates=better gaming experience in general. Either way, the reason I'm "arguing" with you is because you're article can be very misleading to some people. What I'm doing is adding relevant information. The way you write your article seems to make the assumption that it's not he norm for people to be gaming on 60 hz when I think it's quite the opposite.

I'm not saying 60 hz is the best at all. What I'm saying is that the article simply doesn't mention that going above 60fps on 60hz is generally pointless.

[UnsightedScarab]

Well its a good thing The Crew is gonna be 60fps

[Captain86]

Old Post revival
I think this is an illusion of mixing equations which simply doesn't work in real math.

First off your not traveling 147feet at all. Your watching a representation of a computer that is representing 147feet on your screen in the space of inches not feet.

If this representation of how important frame rates were true then theoretically the car should be teleporting like a strobe light every 2 feet or so as you go around the track it should be jumping like a steady blinking strobe ever 2 feet continously at the rate of 60hz. This simply isn't happening as we see on our computers screens.

A couple inches however might even go un-noticed.

We could use the same interpretation and apply this to flying plane simulators that are traveling 1000's of feet per second.

However, the equation is being mixed from real life calculations and applying them to a completely different scale and video representation.

If 2ft per second is represented by 1/4 inch on your screen the frame rate will not be an issue but perhaps all in the mind or simply the mentality of seeing a smoother looking graphic.

It's smoother because the strobe is faster not necessarily because the representation on your screen is missing as much as you think it is.

The strobe effect would look the same as far as smoothness goes even if your car wasn't moving at all.

That's how I see it.

[mr.Timbs]

my mind is blown now i know why a lambo is beating a raid spec on dirt (i run at 13 fps but i think it is smooth)

[Wolfpup3]

*shrug* I'm sure it matters for some people, and in an ideal world I'd love 200fps or whatever, but in reality most people's display devices are capped at 60 (and used to be 30), and I'm fine with a frame rate that's 30fps. Usually anything over the low 20s is great.

[rickersilva]

@fink @invoky @captain86 I would like to try to clarify something I think is important.

About the monitor refresh rate. That only have to do with what you see in the monitor. So, one point right is that it doesn't matter if your game is running at more than 60fps your monitor will only allow 60 images per second. But let me name those, images and not frames.

What can not be missed is that the physics engine and the game is processing, 120 FPS. That means the game is processing 120 snapshots of the simulation with everything it involves from visual effects lighting shadows and so on and also players input, car simulation, suspension, tires, track surface and so on. So it is not pointless having more than 60 events of simulation per second. Regardless of how much the monitor refreshes or how how much you perceive.

And of course it is a simulation, and you Captain, should be glad you are not dead when the car crashes heavily. Take the simulation with as much detail as reality which is what the engineers behind intend to.

[Wolfpup3]

I'm not sure why it would matter if the simulation is running faster if it can't display it.

IMO the reason to aim for higher is so that you can hit 30 or 60fps as minimum or constant frame rate. (Though depending on the game, dips into the low 20s or even below don't much matter).

I tried The Crew on 30fps mode and unlocked or whatever, and it looked a lot better/smoother on 30fps. Other games though look fine unlocked.

EDIT: I should note though that on more powerful systems-or with lower settings-I'm sure the higher frame rate mode would work fine. It looks great at 30fps though, and I could max out the settings nad hit 30fps at 1080p, and it was quite gorgeous.