What streaming actually needs
Streaming services publish their own recommendations, and they are remarkably modest. Standard definition needs around 3 Mbps, high definition around 5, and 4K somewhere between 15 and 25 depending on the service and the content. A 100 Mbps connection can in principle carry four 4K streams at once with room to spare.
| Quality | Per stream | Streams on 100 Mbps |
|---|---|---|
| SD | 3 Mbps | Effectively unlimited |
| HD 1080p | 5 Mbps | About 15 |
| 4K UHD | 15 – 25 Mbps | About 4 |
Theoretical. Leave headroom for everything else the household is doing.
Why it buffers anyway
If your plan comfortably exceeds what the stream needs and it still buffers, the bottleneck is somewhere between the router and the television. In rough order of how often it is the cause:
- 1 Wi-Fi signal at the television — the most common cause by a wide margin.
- 2 An old or overloaded router that cannot keep up with the number of devices.
- 3 The streaming device itself being old or short of memory.
- 4 Another device saturating the connection — a large download or upload.
- 5 Evening congestion on a shared cable segment.
- 6 The streaming service itself having a bad night, which does happen.
Fixes that work, cheapest first
- Move the router out of a cupboard, off the floor and toward the middle of the home.
- Use the 5 GHz band for devices near the router; keep 2.4 GHz for distant ones.
- Plug the main television in with an ethernet cable if you possibly can — it removes the problem entirely.
- Restart the router properly once in a while; uptime of years is not a badge of honour.
- Add a mesh node for a far room rather than upgrading the whole plan.
- Schedule large downloads and console updates overnight.
Only after all of that is it worth considering more speed — and if the household regularly runs several 4K streams alongside video calls, that is a legitimate reason to move up a tier.
Which connection suits streaming
For streaming specifically, almost any modern connection is adequate — this is one area where cable genuinely matches fiber, because streaming is a download activity and cable's weakness is upload. Fiber pulls ahead when the household is also making video calls or uploading while watching.
The two connections that struggle are slow DSL, where a single HD stream can consume the whole line, and geostationary satellite, where high latency makes the start of a stream slow even though it plays acceptably once buffered.