Aspect Ratio, Resolution and Frames per Second - A Small Guide
I see more and more people asking for advice regarding monitor purchases, and usually things such as IPS and TN is brought up, as well as 120Hz and 60Hz, input latency, refresh rate, size, resolution and so on.
I will with this thread/post go further into three factors that I personally find fairly important; frames per second displayed (update frequency), resolution and aspect ratio. Why? Because I think there's a lot of people here who simply knows about these things but have less clue what these things effectively results in.
First and foremost, this is all with the basic outline to improve gameplay experience. To understand this outline one must understand what a "better" gameplay experience means. This can ultimately differ from person to person, but the jist of it is:
Displaying more and accurate information is always better.
I'll try to explain what I mean. More information is fairly obvious; the more we see at a given time the better. Having effectively seen Y amount of information is always worse than having seen 2*Y information. This can be directly translated to pixels, but unfortunately it's not exactly that simple - and that's where the accurate information comes into play. Having 2000 pixels showing only Y information could be worse than having 1800 pixels displaying 2*Y information. The accuracy and relevance of the information is also of great importance.
I'll start with resolution. Resolution is fairly simple at glance; more pixels in a given field means a higher density of information. For example, having 2560x1440 pixels is better because it displays more information in comparison to 1920x1080.
Look at the three screenshots below (in fullsize):
Comparing them you will see that each resolution adds effective information to the display. Look at the shovel below and you will see how details emerge when the resolution is increased.
How effective a resolution ultimately is depends largely on the game you intend to play. Low polygon count together with low resolution textures are example of two factors that can ultimately hinder the amount of information displayed and make the scaling worse (note: not negative, just worse).
Below is a cut from a larger 2560x1440 screenshot taken in Counter Strike: Global Offensive.
As you can see, the larger resolution does very little as the original texture resolution is lower than what the monitor can ultimately display. This brings up the point that I tried to make earlier; the accuracy of the information displayed. Here, a 1440p resolution will not display more texture information compared to a 1080p or even a 720p resolution (unless you move in relation to the texture further away in the game to the point where the texture is displayed with a 1:1 or lower ratio). However, a 1440p resolution will still display a more detailed outline compared to the other two.
Here's another example. This is a low resolution UI element from GR: Future Soldier. A larger resolution would not add anything to the clarity of the text as it is limited by the original texture.
Here is also an important point to make; a larger resolution can effectively display distant objects more precisely. Take a look at the shot below taken from a sniper mission in Far Cry 3. It effectively compares 1280x720 to 2560x1440.
A larger resolution can therefore help you spot and react on distant objects. Here, once more, the outcome depends on the game (or rather the engine). Ultimately, the draw distance of a given game will determine the usefulness of a larger resolution; a short draw distance will make the scaling of a larger resolution worse.
The branches/tree in the foreground is detailed and with high quality textures. The draw distance limits the texture and polygon count of the background trees and as such these are displayed with lower quality. This is an example of how draw distance can limit the scaling of a higher resolution when it comes to distant objects. A higher resolution would simply only increase the quality of the outline of the tree(s) in the background (information displayed).
Aspect ratio is simply the relation between your displayed pixel height and width. The previously discussed resolutions, 1280x720, 1600x900, 1920x1080 and 2560x1440, all have an aspect ratio of 16:9. That means that for every 16 pixels in width, there are 9 pixels in height. Other common aspect ratios are 16:10 and 4:3. These three ratios are the ones I will focus on.
Resolution aside, your aspect ratio can also mean more displayed information. A wider ratio can for example result in that you will see more information to the left and right.
Comparing 4:3 to 16:9:
Comparing 16:10 to 16:9:
The above two shots shows you how much more information is showed with a wider aspect ratio in a first person view game. Titles such as the one above (Team Fortress 2) basically shows exactly why a wider aspect ratio is better for first person view games; you will effectively see more information on the sides. To make the point even clearer, this can be exaggerated through using AMD Eyefinity or nVidia Surround:
However, this does not hold true in all titles. With a from-above view the discussion regarding aspect ratio becomes fairly complicated.
4:3 compared to 16:9:
16:10 compared to 16:9:
Now, it might not look like much but in a MOBA (Multiplayer Online Battle Arena) game such as the one above or in a RTS (Real Time Strategy) game the extra information displayed at the top can be devastatingly important. Here, once more, one must take into consideration the importance of the information displayed; is the vertical information more important than the horizontal? Looking at the second image that compares 16:9 and 16:10 one can understand why some pick the latter for games with a from-above view. To note, the slightly tilted camera angle makes the information at the top of the screen more important than the information at the bottom/edges.
Refresh Rate (effectively Frames per Second):
Many know and understand the difference between a 60Hz and a 120Hz monitor. The former can display a maximum frame rate of 60 while the latter can display a maximum frame rate of 120. The outcome is a smoother image on the 120Hz display in comparison to the former, with the added expense that it's more taxing for your GPU (or rather, that it takes more power to render the image for the display).
It's fairly self explanatory that a 120Hz monitor will display twice as many frames (and in theory, twice as much information) due to the higher refresh rate, but how important is that information? I won't go further into this because it basically dials down to personal preference. I, for example, see no need for a 120Hz monitor in a RTS, MOBA or even a medium/slow first person view action shooter but can certainly understand the advantage of the extra information when it comes to faster first person view shooters (such as Quake or Unreal Tournament). Do note that you still need to react on the displayed information. Having twice as many frames per second will only impact you positively with (in theory) 0.99999... frames faster response, which is ~1/120th of a second. Don't get me wrong; that can be the difference between a victory and a loss, but for the average gamer all 120Hz offers is a smoother experience.
I think the video below speaks for itself when it comes to 30 vs 60 vs 120 frames per second. The original clip can be seen at the end. Would you be able to react?
The above was recorded at 120 frames per second, and then effectively slowed to 30 and 60 frames per second respectively. The part of the clip containing the comparison shots is slowed down to 25%, basically 1/4th of the original speed. That means that the 120Hz sample is played back at 30 frames per second, with a 1:1 ratio to the playback of the clip.
It was my understanding that YouTube was unable to show videos at more than 60 fps. Only things such as VLC and maye even Vimeo were able to do that.
That is completely true. The original clip is essentially the 30Hz recording in real time. It's just to show how fast the camera is actually moving.
The slowed down shots show how much information is lost each step down. 120Hz has 120 frames to display while the 60Hz only has 60 frames in the same time interval.
As I pointed out, in theory, the most 120Hz will offer over 60Hz is ~1/120th of a second (or ~8,3 ms) faster response, but that is only if that information is displayed at the correct interval, essentially after half the time one frame has been shown on the 60Hz screen (right before the 120Hz screen would display the next frame). That is entirely speaking of gaming advantage - a higher refresh rate can still be enjoyable for other reasons (e.g. aesthetics).