How OBS encodes video
When you click “Start Streaming,” OBS takes the scene, encodes it into H.264 (or HEVC) video, and pushes the bitstream to your streaming platform. The encoder is the part of OBS that turns pixels into bits. Two paths exist:
- Hardware encoder: a dedicated chip on your GPU or CPU designed for video encoding. Offloads work from the CPU, runs cooler, leaves more headroom for the game.
- Software encoder (x264): the CPU does all the encoding work. Higher quality per bitrate, much higher CPU load.
For most streamers, the right choice is the fastest available hardware encoder. The quality gap between NVENC and x264 at typical streaming bitrates is small; the CPU-load gap is huge.
NVENC (NVIDIA)
NVIDIA’s hardware H.264 encoder lives on most GeForce GPUs from the GTX 10-series onward. It has its own silicon; encoding at 1080p60 at 6000 kbps uses almost no CPU and very little extra GPU time.
Strengths: consistent quality, low CPU load, available on most gaming PCs.
Trade-offs: on older GTX cards (10-series, 16-series) picture quality at low bitrates is noticeably softer than newer cards. GTX 20-series and later use a newer NVENC chip with better quality per bitrate.
When to pick it: any NVIDIA GeForce GPU from the last several years. Look in OBS under Settings → Output → Streaming → Encoder → NVENC H.264.
Apple VT H.264 / VideoToolbox
macOS’s hardware encoder, available on Apple Silicon Macs and most Intel Macs with hardware acceleration. On Apple Silicon (M1/M2/M3/M4), Apple VT is the only practical choice — there is no x264 path that competes on power efficiency.
Strengths: very low power draw, no fan ramp, available on every modern Mac.
Trade-offs: Apple’s encoder is conservative on quality at low bitrates. At 6000+ kbps the picture is clean; below 3000 kbps x264 can look slightly better.
When to pick it: any Mac, especially Apple Silicon. Read how to stream from a Mac with OBS for the macOS-specific setup.
QuickSync (Intel)
Intel’s hardware encoder lives on most Intel CPUs with integrated graphics. It is separate from the integrated GPU’s display output — even a desktop with a discrete GPU can use QuickSync if the CPU supports it.
Strengths: available on systems where NVIDIA or AMD encoders aren’t present; very low CPU load.
Trade-offs: older generations had quality issues at low bitrates; newer Skylake-derived QuickSync is much improved but still slightly behind NVENC.
When to pick it: Intel-based laptops and desktops where NVIDIA/AMD encoders are unavailable or unreliable. In OBS, look under Encoder → QuickSync H.264.
AMD HW H.264
AMD’s hardware encoder is supported on most modern AMD APUs and GPUs. The implementation has matured substantially in recent OBS versions; older versions had quality issues.
Strengths: available on most AMD systems; low CPU load.
Trade-offs: per-bitrate quality is slightly behind NVENC on most generation-matched hardware. Encoding latency is higher than NVENC at low bitrates.
When to pick it: AMD Ryzen systems, Radeon GPUs from the last few years, or any system where it is the only hardware encoder available.
x264 (software)
x264 is the CPU software encoder bundled with OBS. It is the reference for H.264 quality and is still the best choice when you have CPU cycles to spare and want maximum picture quality per bitrate.
Strengths: the highest quality per bitrate; works on any x86 CPU; configurable presets from ultrafast (low CPU, low quality) to placebo (very high CPU, marginal quality gain).
Trade-offs: CPU-heavy. On a weak CPU, x264 eats the cycles the game needs. On a powerful CPU, you can stay on x264 if picture quality matters more than game performance.
Preset ladder:
- ultrafast: lowest CPU, lowest quality. Use only if x264 is your only option and the system is weak.
- veryfast: the practical default for x264 streaming. Reasonable quality, manageable CPU load.
- fast / medium / slow: higher quality, much higher CPU load. Use on a system with a powerful CPU and a game that does not push it hard.
For new streamers, veryfast is the right x264 preset. medium or higher rarely beats a hardware encoder at typical streaming bitrates.
Side-by-side comparison
| Encoder | CPU load | Power draw | Quality per bitrate | Best use case |
|---|---|---|---|---|
| NVENC (NVIDIA) | Very low | Low | Very good (newer GPUs better) | Most gaming PCs |
| Apple VT (macOS) | Very low | Lowest | Good (Apple Silicon) | Every modern Mac |
| QuickSync (Intel) | Very low | Low | Good (newer generations) | Intel systems without NVIDIA |
| AMD HW H.264 | Very low | Low | Good | AMD-only systems |
| x264 (software) | High (preset-dependent) | High | Best at typical streaming bitrates | Powerful CPUs, low-motion content |
How to pick in practice
- Open OBS Settings → Output → Streaming.
- Pick the encoder that matches your hardware (NVENC for NVIDIA, Apple VT for Mac, QuickSync for Intel, AMD HW for AMD).
- Set rate control to CBR, keyframe interval to 2 seconds, audio to 160 kbps AAC.
- Pick a video bitrate your upload can hold with 30% headroom. Use the stream bitrate calculator if unsure.
- Run a 10-minute test recording. Open View → Stats and confirm both “Missed frames” and “Dropped frames” stay near zero.
- If everything is clean, stream. If skipped frames appear, the encoder is the bottleneck — drop FPS before resolution, or lower in-game graphics.
If your system has both a hardware encoder and a powerful CPU, try both at the same bitrate and see which your viewers prefer. The honest answer is usually “they cannot tell” at 1080p60 / 6000 kbps.
Encoder settings that actually matter
The encoder choice matters more than any individual setting on the encoder. Within a given encoder, the only settings that meaningfully affect quality and stability are:
- Rate control: CBR for live streaming.
- Keyframe interval: 2 seconds.
- Video bitrate: the right number for your upload and platform.
- Preset (x264 only): ultrafast to veryfast for streaming; faster presets on weak CPUs.
Encoder-specific sliders like “B-frames,” “Look-ahead,” or “psycho-visual tuning” tweak the quality vs CPU tradeoff by a few percent; they do not fix fundamental problems. Start with defaults, get the stream stable, then experiment.
When to use x264 over a hardware encoder
Despite everything above, there are real cases for x264 on a modern PC:
- Low-motion content: art streams, tabletop RPGs, code streams, podcasts. x264 at lower bitrates preserves more detail than hardware H.264.
- Slow games or VOD-style content: a turn-based strategy game running at 30 fps is a good fit for x264 medium/slow.
- The hardware encoder is buggy or unsupported: rare, but older OBS versions on some hardware have had encoder regressions. x264 is the universal fallback.
For fast-paced games on a typical gaming PC, the hardware encoder is the right pick. Save x264 for content where its quality advantage is visible.