


 When I download a file from internet, firefox shows that the download speed is 550 Kbits/sec. How does this speed translate or relate to 15MB dowload speed?Category:Speed Information

Filesize (how big a file is on your computer) is usually measured in units of "kilobytes," "megabytes," and "gigabytes."
In this computing (binary, but not data transfer) usage, 'K' (uppercase) represents a multiplier of 1,024. Other abbreviations use this same base of 1,024:
 1 KB (one KiloByte) = 1,024 Bytes (approximately 1 thousand Bytes)
 1 MB (one MegaByte) = 1,024 KB (approximately 1 million Bytes)
 1 GB (one GigaByte) = 1,024 MB (approximately 1 billion Bytes)
Data transfer speed on the other hand is expressed in bits. In bit rates the abbreviations are as follows:
 1 kbps = 1,000 bits per second
 1 Mbps = 1,000,000 bits per second.
 1 Gbps = 1,000,000,000 bits per second.
kbps (kilobits/sec) means thousands of bits per second mbps or Mbps (megabits/sec) means millions of bits per second gbps or Gbps (gigabits/sec) means billions of bits per second (where "billion"= 1,000,000,000.00") tbps (terabits/sec) means trillions of bits per second (as in "terabit router" or "terabit speeds") pbps (petabits/sec) means quadrillions of bits per second.
Because there are 8 bits in a Byte, to get a bitrate (speed) from values given in Bytes, you must multiply the total number of Bytes by 8.
Conversely, to get KB/s values from bit rates, you must divide the total number of bits by 8, then divide by 1,024.
For converting KB/s to kbps (bit rate from Byte values), the equation is basically as follows:
<K> KiloBytes * 1,024 = <t> total Bytes
<t> total Bytes * 8 = <b> bits
<b> bits / 1,000 = <k> kilobits
30 KB/s * 1,024 = 30,720 Bytes per second
30,720 Bytes per second * 8 = 245,760 bits per second
245,760 bits per second (bps) / 1,000 = (approximately) 246 kbps (245.8 kb/s)
And for kbps to KB/s (Byte values from bit rates), you switch the equations: <k> kilobits per second * 1,000= <b> total bits per second; <b> bits / 8 = <t> total Bytes per second; and <t> / 1,024 = <K> KiloBytes per second. For example: 128 kbps (k) = 128,000 bits per second (k*1000=b) = 16,000 Bytes per second (b/8=t) , or about 15.6 KB/s (t/1,024=K) .
So a 512\128 internet connection would give you about 62.5 KB/s maximum download, and about 15.6 KB/s upload (max). And a 1500\128 service (1.5 mbps download cap) would give you about 183.1 KiloBytes per second, maxium
Written by Last updated on 04.06.07




