Bandwidth and transfer time

How long a transfer actually takes on a given link, and how many concurrent streams a connection carries before it is the bottleneck.

In megabits per second. A gigabit port is 1000.

TCP/IP framing and retransmits. 5-10% on a healthy wired link.

In gigabytes.

In megabits per second. 4K video is roughly 25.

A link run to 100% has no room for anything interactive.

Reset
920.0 Effective throughput Megabits per second after framing.
115.0 Real-world speed Megabytes per second — what a copy dialog shows.
29 Streams the link carries
That transfer
Transfer takes (seconds) 435
In minutes 7.2
In hours 0.12 hours
Concurrent streams
Usable after headroom 736.0
Streams the link carries 29
Those streams use Megabits per second. 725.0
Spare after them 195.0

Megabits are decimal and so are gigabytes here, because that is how link speeds and drive capacities are both quoted. Substituting 1024 anywhere in this chain gives an answer about 7% out that looks entirely plausible.

Overhead covers framing and ordinary retransmission, not a saturated link. Once a connection is at capacity, latency and loss climb and the effective rate falls further than any fixed percentage predicts — which is what the headroom field is for.

Nothing here is sent anywhere; the numbers live in the page address.