A recent business proposal required me to calculate the time taken to download huge files. Being a BSNL Dataone user, I was comparing it with various plans including the Home unlimited plan for Rs.900.
1 MB = 1024 KB = 1024 * 1024 bytes
= 1048576 bytes
= 1048576*8 = 8388608 bits
|Bandwidth in K bps (Kilo Bits Per Second)||Speed in Kilobytes per Second||Time taken to download a 1MB(1024Kilobyte) file
under ideal conditions in seconds
|256 K bps = 256 * 1024 bps = 262144 bps||256/8 = 32 KB/S||8388608/262144 = 32|
BSNL offers 256Kbps guaranteed speed with a maximum of 2Mbps. So you can theoretically download a 1Mb file in …well under 4 seconds. So that’s under ideal conditions. I have seen download progresses for my 256Kbps connections at the range of 200KB/s. A lot depends on the server’s bandwidth too.
So how much does a 1GB file take to download with a 1 Mbps connection ? From the above table, 8 seconds for 1MB = 8 *1024 for 1GB = 8192 seconds = 136.53 minutes = approximately 2 and a half hours..
Update as on 14-3-08
I’m getting a download speed of 312Kb/s on my home 500 plan which means the speeds are crossing the 2Mbps speeds.