Mbps in the internet package and MB/s on the download screen are different units. Comparing the numbers directly can give the illusion that the connection is eight times slower.
Basic approach
A byte is eight bits. In decimal units, 100 Mbps theoretically corresponds to 12.5 MB of data per second. In practice, protocol overhead, retransmission, server limit, and storage performance may reduce the available file transfer rate.
Application steps
- Check whether each measurement uses bits or bytes and the capital letter B.
- Convert file size and transfer rate to the same unit.
- Calculate the estimated time based on the actual sustained file transfer rate, not the capped capacity.
Practical example
Decimal 1 GB file transferred at 10 MB/s in approximately 100 seconds; connection preparation and final operations may be added to this time. The ideal time for the same file on a 100 Mbps connection is 80 seconds, but this is not a guarantee.
Interpret the result correctly
Binary units such as MiB and GiB also affect the result. Do not extend the short-term peak value of the speed test over the entire duration of the large file. If there is a slow disk or single connection constraint, upgrading your network package may not make the expected difference.
Source and follow-up reading
Protocol or command details: RFC 2330. The steps and example scenario are IPScans editorial narrative.