Bandwidth & Bottleneck Planner

Adding up every device's peak demand gives a figure nobody ever reaches. Four people who each need 25 Mbit/s for 4K do not need 100 unless all four watch at once, and mostly they do not.

What matters is concurrent demand — how much is being asked for at the same moment. That is why each row here has a "how often" figure, and why the total and the realistic peak are shown separately.

Streaming is not the problem people think

4K streaming is about 25 Mbit/s and adapts down when the connection is busy. Video calls are a few Mbit/s. The things that genuinely saturate a connection are backups, cloud sync and software updates — because they take everything available and have no reason to be polite.

They also mostly run upward, and upload is usually the smaller number by a wide margin. A connection sold as 500 down and 50 up will feel broken during a backup while the download figure sits idle.

Latency, not bandwidth

Most complaints about a "slow" network are about latency and jitter rather than throughput. A video call needs 4 Mbit/s and consistent delivery; it degrades when a backup fills the queue, not because the bandwidth ran out. Adding capacity does not fix that — prioritisation does.

The path is only as fast as its narrowest hop

A gigabit switch does nothing for a device connected over Wi-Fi at 200 Mbit/s. A 10-gigabit server does nothing behind a gigabit uplink. Upgrading anything other than the narrowest point changes nothing at all, which is why the second half of this page exists.

Wi-Fi figures here are real-world throughput rather than the headline rate. A link negotiating 866 Mbit/s delivers roughly half that in practice, and less with distance or other clients on the radio.