People who are unfamiliar with the technical jargon involved are often confused when trying to discuss internet speed(bandwidth), file sizes, and the relationship between the two. But, luckily for you, we’re here to help! So first, a few definitions:
b – a bit – The foundation of the internet. the “speed” of an internet connection is typically measured in bits per second, although bandwidth is really the accurate term, as bits per second is constrained by the width of the pipe, not the “speed” of the packets (the packets are moving at the speed of light down fiber lines, and the speed of light is a constant).
B – a byte – There are 8 bits in a byte – file size is typically defined in terms of bytes instead of bits. Check out: http://en.wikipedia.org/wiki/Byte This makes an 8mbps(megabits per second) internet connection capable of downloading 1mB in one second.
k = kilo = 1,000
m = mega = 1,000k or 1,000,000
g = giga = 1,000m or 1,000,000,000
(if you don’t like this system, please take it up with the romans, you can find them here: http://en.wikipedia.org/wiki/Decline_of_the_Roman_Empire)
It also may be worthwhile to understand the difference between bandwidth and latency.
People generally talk about internet speed in terms of bandwidth – if the Internet was a river, this would be the width of the river, which is part of the equation that determines how much water can flow by in a given period of time.
Latency on the other hand is the amount of time it takes a packet of information to get from one place, to another, and back to the originator. We can measure this by doing a ‘ping’ which will yield a result normally expressed in milliseconds (1/1000th of a second). Because the internet is just electricity running down wires, the speed stays constant, and can’t really be affected by an internet service provider. A person’s latency to a destination half way around the world will naturally be worse than their latency to their next door neighbor.
There is however, a catch. If a person’s bandwidth is being maxed out by one application, it may cause the latency to increase for other applications, that have to “wait in line” before being allowed through. This is why effective network management is so important, not just at the level of the internet service provider, but in the home as well. Even though online gaming requires very little bandwidth (all the media for the game is part of the installation files, so all that is being sent of the internet is positional mathematical data) – it does require low latency (we want the effect of our actions to happen in as close to real time as possible). If a poorly managed network is overwhelmed with Netflix traffic (the human eye can see up to 60 frames, or pictures, per second) then the latency of other applications like online gaming may be affected.
To get a better idea of the relative sizes of different files, check out the following list:
1 byte (or 8 bits) is a single keystroke or (non-accented) character; or a number from 0 to 255
70 bytes is about equal to a single line of text.
1,000 bytes (or 1kB) is half a page of unformatted text; or a very short email; or an icon or small button image.
10,000 bytes (or 10kB) is a typical 80-word plain text message. This is also approximately the amount of data per second needed to play most online games. Since internet speed is measured in bits not bytes, multiple 10kB by 8 to get 80kbps. Nowadays we talk about internet speed in mbps, so we would say .08mbps. (Yes, that is .08, like basically nothing)
30,0000 bytes (or 30kB) is a 5-page word-processor document; or a typical HTML web page; or traditionally, the maximum recommended size for an image on a web page (maybe 640 x 480 pixels JPEG);
100,000 bytes (or 100kB) is the maximum recommended total of all the elements on a single web page, including images and HTML (as of 2010, it’s a bit higher now).
500,000 bytes (or 500kb) is a reasonable size for a PDF document someone might choose to download; or perhaps two 1280×960 JPEG photos taken on a smartphone.
1,000,000 bytes (or 1mB) is about 1 minute of near-CD quality audio; or the complete comedies and tragedies of Shakespeare when compressed into a zip file.
5,000,000 bytes (or 5mB) is about three-minute of high quality audio; or 1 minute of low-resolution video; or all the Wikileaks cablegate files released by mid-Dec 2010; or a 20-page PDF; or the complete works of Shakespeare (uncompressed)
10,000,000 bytes (or 10mB) is typically the maximum size of an email that you can expect all recipients to receive, regardless of who their provider is.
25,000,000 bytes (or 25mB) the approximate size of the 26-volume 1911 edition of Encyclopaedia Britannica.
100,000,000 bytes (or 100mB) is about how much data you will have used after playing an online game for between 2 to 4 hours depending on the game.
700,000,000 bytes (or 700mB) is the maximum amount of data on one CD-ROM; or a two-hour movie at standard definition.
4,000,000,000 bytes (or 4gB) is the amount of data on a DVD-ROM; or the maximum amount of RAM (working memory) a 32-bit processor can use directly.
16,000,000,000 bytes (or 16gB) is the amount of space on a $10 USB flash drive (“memory stick”).
150,000,000,000 bytes (or 150gB) is the amount of data consumed during a month at which some nefarious internet providers start charging their customers overage charges – sometimes as high as $1.50 per gB of overage!
Now you know. And knowing is half the battle.