Fps?

[krokadil]

Hey, folks!

This may seem like a real newbie question, but I have never had a computer capable of handling big games so I have pretty well never gotten past Wolfenstein 3D and DOOM. Consequently, I have NO IDEA what to make of all the settings for my new video card.

Here we go - I know that FPS means Frames Per Second, but WHAT does that mean in a practical gaming setting? What is a standard rate? In my new addiction - Unreal Tournament (the first, I'm still behind the times) - there is a place where you can set your minimum FPS.

I ran 3DMark hoping that it might tell me what a good setting would be for my machine, and though none of the tests ever ran below 24FPS I still have no idea what to make of that.

My card is a PCI Radeon 7500LE 64 and the rest of my system is in my signature. I have downloaded all the new drivers - in case you were wondering.

Any advice and help from you hardcore gamers would be appreciated!

[reboot]

24fps is respectable. Ideally, the human eye can detect "flicker" in anything slower than 32fps (the speed that television scans at), so you want to get it higher than that if possible.
Depending on how much stuff is going on on the screen, the rate will vary a lot. If it's a fairly static image, the fps will go way up, but if theres movement in most objects on the screen, the fps will go down.

[sleepypost]

check what refresh rate your monitor is set at (display properties). the number will be in Hz (hopefully 60Hz or better). Set your minimum FPS as close to that number as possible, that is unless you want flicker and eye-strain. keep in mind a too high FPS setting will cause performance slowdown so test it out to see what is best.

[sleepypost]

Originally posted by reboot 24fps is respectable. Ideally, the human eye can detect "flicker" in anything slower than 32fps (the speed that television scans at),

??? my card runs games at about 90 FPS. Also i thought TVs displayed at 60 FPS. I dont know about Canada but here it seems 60 FPS is standard for everything. (ie 60 Hz, as in frequency).

[krokadil]

So if I set my FPS to 32 then I shouldn't notice any hiccups? What happens when you go higher than that? How can there be any difference if your eye cannot perceive it?

What is the trade-off between memory and FPS settings? Will I get better game performance with a lower FPS (no lags and such in play) or does it not matter? Should I just set the number as high as possible?

If your FPS should match your refresh rate then why are you able to set it at all in the game?

One question just brings more questions...



BY THE WAY - let me open up a whole new vein here -

Should I choose D3D or Open GL in Unreal? My card supports both.

[Spyda]

i thought the human eye saw at 60 fps, and playing all these high fps games i can start to detect flicker on Xbox and PS2 games, its pretty bad actually

[Nuclear Krusader]

Originally posted by krokadil BY THE WAY - let me open up a whole new vein here - Should I choose D3D or Open GL in Unreal? My card supports both.

OpenGL is way better.

[Alienware_Dude]

Just enable v-synch, and it will limit the FPS to the monitor refresh.

[sleepypost]

Spyda, yea am i the only other one????? 60 fps is crap i thought. My eyes can EASILY detect 60 FPS. It hurts to watch! Anything below 75 FPS is too low... 32? that is WAY too low i thought!

[Blakhart]

I'm with you, anything less than 100 I can tell.

[Q-Frost]

I'm Also A FrameFreak, If I Can't Game In At LEAST 70 FPS My Eyes Annoy Me To No End, And With Me Also Liking AA Too Much That Means My Poor Old TI-4200 Is Getting A Workout :P

[sleepypost]

OK Reboot, you have some explaining to do...

[Spyda]

maybe playing high fps games in a poorly lit room has just damaged all our eyes

[reboot]

FPS and hz are directly related.
Without trying to get too technical...
The frame rate of a video source is how fast the source repaints the screen with a new frame. The (M) NTSC system screen is repainted about once every 30th of a second for a frame rate of about 30 frames per second. For (B,D,G,H,I) PAL, the frame rate is 25 frames per second. For computer displays, the frame rate is now usually 72- 75 frames per second or more.
Frame rate conversion is the act of converting one frame rate to another. One real example that poses a difficult problem is that the frame rate of (M) NTSC, about 30 frames per second, is different from a typical computer's display, which may be anywhere from 72 to 75 frames per second (or Hz if you prefer). Therefore, some frame-rate conversion process must be performed before (M) NTSC video can be shown correctly on a computer display. Without frame rate conversion, the screen might look as if it "stalls" every now and then. If there is motion within the video, the objects that are moving may appear to be cut in half.
The human eye retains an image for a fraction of a second after it views the image. This property (called persistence of vision) is essential to all visual display technologies. The basic idea is quite simple, single still frames are presented at a high enough rate so that persistence of vision integrates these still frames into motion.


Motion pictures originally set the frame rate at 16 frames per second. This was rapidly found to be unacceptable and the frame rate was increased to 24 frames per second. In Europe, this was changed to 25 frames per second, as the European power line frequency is 50 Hz. (Just as an aside, 24 frame/second American movies are routinely broadcast at 25 Hz in Europe ... the 4% difference does not seem to bother anyone!)


When NTSC television standards were introduced, the frame rate was set at 30 Hz (1/2 the 60 Hz line frequency). Then, the rate was moved to 29.97 Hz to maintain 4.5 MHz between the visual and audio carriers. (As we will see -- this decision has lead to some problems in developing an HDTV standard.) Movies filmed at 24 frames per second are simply converted to 29.97 frames per second on television broadcasting.


Now, there is a glitch. For some reason, the brighter the still image presented to the viewer ... the shorter the persistence of vision. So, bright pictures require more frequent repetition. If the space between pictures is longer than the period of persistence of vision -- then the image flickers. Large bright theater projectors avoid this problem by placing rotating shutters in front of the image in order to increase the repetition rate by a factor of 2 (to 48) or three (to 72) without changing the actual images.

Unfortunately, there is no easy way to "put a shutter" in front of a television broadcast! Therefore, to arrange for two "flashes" per frame, the flashes are created by interlacing.


The basic idea here is that a single frame is scanned twice. The first scan includes only the odd lines, the next scan includes only the even lines. With this method, the number of "flashes" per frame is two, and the field rate is double the frame rate. Thus, NTSC systems have a field rate of 59.94 Hz and PAL/SECAM systems a field rate of 50 Hz.


Although interlacing sounds like a great idea -- a number of aberrations appear due to the fact that you really do not have a frame rate of 50/60 Hz. For example, vertically adjacent picture elements do not appear at the same time. If the scene is moving, then this creates a series of serrations on the edge of moving objects. Other aberrations include such things as misalignment (where the horizontal edges of one scan do not match with the next), and interline flicker (where slight mismatches between subsequent lines cause a shimmering effect).


The other situation that must be considered is rapid motion. If the still frame images are presented at too low a rate, rapid motion becomes jerky and odd looking. This is especially a problem in action movies -- where high speed chase scenes are common. However, as of yet, there has been little interest in converting movie projectors to either 29.97 or 30 Hz due to the large investments in such equipment.

Clear as mud?

[Spyda]

oh no ive gone crosseyed

[Andrewxcav]

on an LCD, 60 hert refresh rate wont be any different than 60FPS on an infinate refresh rate, because it never goes black, but a CRT goes black between refreshes, and 60 herts hurts

[sleepypost]

reboot,

that is a very nice explaination! however, so we are in agreeance that it is 60 FPS now standard even though it is only 30 images per second (each one is doubled)? i think in America the stabdard termanology for refeshes is 60 FPS at 60 Hz, not 30 FPS at 60 Hz.

[reboot]

"The basic idea here is that a single frame is scanned twice. The first scan includes only the odd lines, the next scan includes only the even lines. With this method, the number of "flashes" per frame is two".
It's still 30 fps, although there are 60 "flashes" per second, making it appear smoother.

[sleepypost]

ok, 30 frames as in 30 unique frames, right? but 60 flashes as in 60 frames per second.

[reboot]

Sorta, it's 60 flashes, but still only 30 fps as the definition of fps is a FRAME per second, not the number of flashes. They could triple or quadruple scan it, and have 120 flashes, but it would still only be 30 fps.