Download Large Files
Test the speed of the network by up- and downloading large files.
You can download two files, the first is one megabyte in size, and the second is ten megabytes. Once
you have these files, you can easily test the speed of FTP transfers to and from your home directory. If it
takes x seconds to upload the ten megabyte file, then the transfer rate is
1/(10x) megabytes per second.
The files can be downloaded either either uncompressed, or as .gz GZIP compressed files. If you
download the uncompressed files, then it is just as easy to determine the transfer using HTTP instead
of FTP. If you download the compressed files, then you will probably require a calculator to
determine the speed of the transfer in megabytes per second.
Alternatively, you can download a short video clip
Bundesliga-Manager Video (19168352 bytes).
- Both the 1 MB and the 10 MB files consist of lines containing 1023 random numbers between 0 and 9
in ASCII format. Together with the newline characher, each line therefore contains exactly one
kilobyte of data.
- The 1 MB file contains 8192 lines, so that the entire file contains exactly 1048576 bytes, or
one megabyte. Similarly, the 10 MB file contains 81920 one kilobyte lines, so that the entire file
contains 81920 one kilobyte lines, making a total of 10485760 bytes, or exactly 10 megabytes.
- Lines in Microsoft text files are terminated with not one character but two, namely a carriage
return character and a linefeed character. It follows that if these files are downloaded in ASCII
mode, the one MB file will have 1048576 + 8192 = 1056768 bytes, and the ten MB file 10567680 bytes.
- There will usually be small variations in the times you measure if the same file is transferred
several times. This is due to other traffic on the network.
- Depending on whether or not FTP transfers are performed using ASCII or BINARY modes, there may be
considerable performance differences.
- You can always test the transfer rates for FTP uploads, irrespective of FTP quotas. If the
transfer quotas are exceeded, the FTP daemon will only notice this after the upload has
taken place, and then delete the file without further comment. This is because the FTP daemon
cannot know how large the file being transferred is until it has been completely uploaded. To test
the download transfer rates, on the other hand, you cannot exceed the FTP quotas.