Seven rules do most of the work. They are named so they can be argued with.
The 70% Headroom Rule
Set your stream bitrate to about 70% of your real sustained upload speed, not 100%, because the remaining 30% is what absorbs a bitrate spike or a moment of packet loss before viewers see a buffer.
A speed test reports a peak, not a floor. Live video is bursty: a busy scene can briefly demand well above the average bitrate you set, and mobile uplink dips whenever you round a corner or a tower hands you off. If you have already spent every kilobit, that spike has nowhere to go and the encoder queue backs up, which is the moment a stream stutters or drops to a BRB screen. Leaving roughly three tenths of the pipe unspent is the cheapest stability you can buy, and it is why a build that "should" hold 1080p60 on paper often will not in the field. StreamPartPicker plans every build against this budget rather than against a speed test number.
Answers: what bitrate should I use for my upload speed · why does my stream keep buffering when my internet is fine · how much upload speed do I need to stream
The Twitch 6000 Ceiling
Twitch's standard ingest tops out around 6000 kbps, which is enough for a good 1080p60 stream and not enough for 1440p, so buying a sharper camera does not raise a Twitch stream past 1080p.
Bitrate, not sensor resolution, sets how a live stream looks. Twitch accepts higher bitrates from some channels but plans around roughly 6000 kbps for everyone else, and 1440p60 needs meaningfully more than that to avoid smearing in motion. The result is a common and expensive mistake: a creator upgrades to a 4K camera, sees no improvement, and concludes the camera is bad. The fix is either a platform with more room (YouTube allows far more, Kick sits in between) or Twitch Enhanced Broadcasting with HEVC. This is why StreamPartPicker asks which platform you stream to before it tells you what quality your build holds.
Answers: what is the max bitrate for Twitch · can you stream 1440p on Twitch · why does my 4K camera look bad on Twitch
The H.265 Discount
H.265 (HEVC) reaches the same visible quality at roughly 70% of the H.264 bitrate, which is why a bonded IRL rig sending HEVC over SRT can hold a tier that the same connection cannot hold in H.264.
The saving is real but it only helps where the bottleneck is the wire. On an IRL backpack sending SRT to your own relay you control both ends, so HEVC turns a marginal 1080p60 into a comfortable one. On a direct-to-platform push it only helps if the platform ingests HEVC, which is exactly what Twitch Enhanced Broadcasting added. Encoding HEVC also costs more compute, so a phone or a small encoder may drop frames reaching for it. We apply the discount only when the whole chain supports it.
Answers: is H.265 better than H.264 for streaming · does HEVC reduce bitrate · should I stream in HEVC
eSIM Is Failover, Not Bonding
Adding a second SIM to a phone gives you a backup connection, not a bigger one: a phone uses one data connection at a time, so two carriers only add bandwidth when a bonding device or service actively combines them.
This is the single most common misunderstanding in IRL streaming, and it costs people money. Bonding means splitting one video stream across several links at once and reassembling it at the far end, which requires software or hardware built for it: belaBOX or a LiveU, Peplink SpeedFusion, Speedify, or a bonding-aware relay. A dual-SIM phone does none of that. What a second carrier does buy you is coverage: when one network dies in a parking garage, the other may not. That is worth having, it is just not more bitrate.
Answers: does dual SIM increase upload speed · can I bond two phones for IRL streaming · is eSIM the same as bonding
A Real Camera Needs Capture
Any camera whose only video output is HDMI needs a capture card before a computer can use it as a webcam, so the true cost of a mirrorless streaming camera is the camera plus a capture device plus a clean-HDMI-capable body.
Webcams present themselves as USB video devices, so software sees them immediately. Cameras output HDMI, which a computer has no way to ingest without hardware that converts it into a USB video stream. Three things then have to be true: the camera must output a clean feed with no menus overlaid, it must not shut off after a recording-limit timeout, and it needs constant power rather than a battery. Skipping any of them produces the familiar result of a camera that works for ten minutes and then stops. Our compatibility engine raises this before you buy, not after.
Answers: do I need a capture card for my camera · how to use a DSLR as a webcam · why does my camera turn off while streaming
The Relay Turns a Drop Into a BRB
Sending a mobile stream to your own SRT relay first, instead of straight to the platform, is what turns a lost connection into a short BRB screen rather than an ended broadcast.
Platforms end a broadcast when ingest stops. A relay sits between you and the platform, holds the platform-side connection open, and shows a holding screen while your uplink recovers, so your viewer count and your session survive. It is the difference between a stream that recovers from a tunnel and one that has to be restarted, retitled, and re-found by the audience. Every mobile build we plan treats a relay as part of the kit rather than an upgrade.
Answers: why does my IRL stream end when I lose signal · do I need a relay server for IRL streaming · what is an SRT relay
Bitrate Beats Resolution
Below about 6000 kbps a clean 720p60 stream looks better in motion than a starved 1080p60 one, so the honest move on a weak connection is to drop resolution rather than send a smeared bigger picture.
Encoders spend their bitrate budget on change. Fast motion, confetti, grass, a moving camera: all of it eats bits. Ask for more pixels than the budget supports and the encoder pays for them by throwing away detail everywhere, which viewers read as mush. The same budget spent on fewer pixels produces a sharp, stable picture. IRL streams are almost always motion-heavy, which is why our verdicts are conservative about jumping a tier just because the encoder technically supports it.
Answers: is 720p60 better than 1080p30 · why does my stream look blurry when I move · should I stream 1080p or 720p