720p or 1080p? Resolution, bitrate, CBR and NVENC explained

Almost every “my stream looks bad” problem comes down to four settings that people set by guessing. Here's what each one actually does, and why turning them all up is the most common way to make your stream worse.

Bitrate: how much data you send per second

Measured in kbps. It is the single biggest factor in how your stream looks, and it matters most in motion — a still webcam looks fine at any bitrate, while a fast shooter at low bitrate turns into a smear of blocks. That smearing is your encoder running out of data budget.

The hard limit is your upload speed, not your download. Run a speed test, look at the upload figure, and use at most 70–75% of it. The rest is headroom for everything else on your network — and for the moments your ISP has a bad minute. A stream that runs at 95% of your upload will drop frames the first time someone else in the house opens a video.

CBR vs VBR — and why Twitch wants CBR

CBR (Constant Bitrate) sends the same amount of data every second, no matter what's on screen. VBR (Variable Bitrate) spends more during busy scenes and less during still ones, which is more efficient in the abstract.

Use CBR for live streaming. Every major platform expects it, and Twitch requires it. The reason is that live delivery has no time to buffer around a spike: when VBR suddenly decides an explosion needs triple the bitrate, that burst hits an upload pipe that can't absorb it, and viewers get buffering. VBR is for recording files to disk, where nothing is time-critical. If you're seeing “cbr in obs” in a settings guide, this is why — it's in Settings → Output → Rate Control.

NVENC and the other encoders

Encoding is the work of compressing your video, and you choose what does that work:

• NVENC — a dedicated encoding chip built into NVIDIA GPUs. It is separate silicon from the cores that render your game, which is the whole point: it encodes essentially for free as far as your framerate is concerned. If you have any modern NVIDIA card, use this.
• AMF / VCN — the AMD equivalent. Same idea.
• Apple VT — the hardware encoder on Apple Silicon Macs. Excellent.
• QuickSync — Intel's, built into most Intel integrated graphics. A perfectly good option on a laptop with no dedicated GPU.
• x264 — software encoding on your CPU. The best quality per bitrate at slow presets, and the worst possible choice while gaming, because it competes with the game for the exact same CPU.

The short version: if you have a hardware encoder, use it. Modern NVENC is close enough to x264 in quality that the difference is invisible at streaming bitrates, and it costs you almost no game performance. Choosing x264 while gaming is the most common cause of dropped frames and stuttering.

Resolution and framerate: the trade you're actually making

Resolution and framerate both consume the same fixed bitrate budget. More pixels or more frames with the same bitrate means less data for each one — so “1080p60” at a low bitrate looks considerably worse than 720p60 at the same bitrate.

• 720p60 — the right default for most new streamers on most connections. Fast games stay sharp, and 60fps matters far more than resolution for anything with motion.
• 1080p60 — needs real bitrate to hold up. Worth it if your upload comfortably supports it.
• 1080p30 — fine for Just Chatting, cooking, art, anything slow. A bad choice for shooters.
• 936p / 900p — an underrated middle ground when 1080p is just out of reach.

What's new in 2026

Twitch's Enhanced Broadcasting lets your GPU send several quality variants directly to Twitch rather than relying on server-side transcoding. On top of it, Twitch launched Dual Format and 2K streaming in June 2026:

• 2K (1440p) at 9 Mbps using HEVC — available to Partners and Affiliates. HEVC is a newer codec that delivers more quality per bit than the older AVC/H.264.
• 1080p at 7.5 Mbps using AVC — the standard high-quality path.
• Dual Format — streaming horizontal and vertical simultaneously, so mobile viewers get a vertical-optimised view. Rolling out to all streamers.

None of this changes the advice above. 1440p at 9 Mbps requires an upload of roughly 12 Mbps or more to be safe, and it is worth nothing if it buffers. Get a stable, well-encoded 720p or 1080p working first.

The two settings people forget

• Keyframe interval: 2 seconds. Not 0, not auto. Every live platform expects a keyframe every 2 seconds, and getting this wrong causes odd playback and thumbnail problems.
• Downscale filter: Lanczos (or Bicubic). If your canvas is 1080p and your output is 720p, OBS is resizing every frame — and the default filter is not the sharpest one available. It costs almost nothing to change and it visibly helps.

Now put real numbers in: the OBS settings calculator does the arithmetic, and fix dropped frames and lag covers what to do when the numbers are right and it's still stuttering.