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Comment by worldmerge | Hacker News Reader

If you haven't just used OBS you definitely should check it out. It's an incredible piece of software. I can screen cap multiple browsers and get a webcam feed and be at ~4% CPU usage. To put that in perspective I just made an app with OpenFrameworks (C++) that just gets my camera and it uses ~6% of my CPU.

OBS is amazing.

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As a counter anecdote - my 2015 MacBook Pro stutters within 30-40 seconds of OBS streaming a 1080p feed to YouTube.

Is there anything to tweak? Or is my machine too old?

Not sure, you may want to drop to 720p and maybe lower your bitrate. For my latest project I was using a Macbook pro 2015 to test it, running my app and streaming at the same time fine. I was running Windows 10 though on the mac. If you're running Mac OS try using a utility like SMC Fan Control to set the fan RPM high. Mac OS by default wants to be as silent as possible which could be leading to some performance issues.

I'm very new to streaming so take what I say with a grain of salt.

A lower bitrate (=better quality assuming constant file size) requires your encoder to work harder. If anything you want to use faster settings with higher bitrates (=lower quality). Some encoders let you cap the bitrate but what this does is basically ruin video quality in scenes where the bitrate cap has been exceeded, it doesn't actually make it less CPU intensive.

Make sure you're using hardware encoding if you can. Using the CPU encoder can be higher quality, but it can't beat the dedicated hardware on your GPU for encoding in terms of performance.

Even a first-gen Raspberry Pi 1 is able to encode 1080p30fps video with its hardware encoder.

Most newer gpus can encode video on the gpu. This helps tremendously.

A 2000 series NVidia GPU can encode 4K/60 at less than 5% load (and that’s gpu loaf, cpu loaf is essentially zero)

The MacBook can do none of those things, it’s old school cpu encoding.

In macbooks you can use igpu for encoding, imo works pretty well. Not sure if OBS supports that, but I was able to use it with ffmpeg

I have a 2015 mbp and just setup obs on it a few days ago. Cpu encoding is the only option.

I was in the same boat. Switched to a T495 ThinkPad with AMD Ryzen 7 PRO 3700U w/ Radeon Vega 10 Gfx, and now my macs feel like toys. Unbelievable power. Would never imagine a laptop could do any of things OBS is able to deliver without breaking a sweat.

OBS supports hardware encoding ironically on Intel integrated graphics, but doesn't on discrete graphics. So a much better graphics chipset in a macbook is likely to be a hinderance for this.

It supports nvidia gpus at least, for sure

Nvenc is supported, even says in the change log that they improved the messages they show if you are using old nvidia drivers.

NVENC is not supported on macOS because Apple does not expose it in their VT toolkit that OBS is required to use to access hardware encoders.

The CPU/GPU usage for streaming depends mostly on the encoder that you're using. Programs like OBS allow you to use different encoders with different settings. This will place a very different load on your system. Eg x264 slow at 1080p would use a lot of CPU resources on most CPUs. On the other hand, if you have an nvidia GPU capable of nvenc and use that then you get next to no CPU usage. Same goes if you have an Intel CPU with an iGPU and use QuickSync or AMD's GPU encoder.

I'll say that even most modern desktop CPUs would use about a CPU core when encoding x264 even on fast preset at 1080p. It's pretty CPU intensive. That's why hardware encoders such as nvenc are popular. You most likely want to check what kind of encoder you're using. Maybe there are no other options than x264. In that case you might want to drop encoder settings and perhaps the resolution.

Sounds weird. We are using an old 2015 MacBook Pro for 1080p streams at work. We stream multiple webcams, browser capture, Teams capture and HDMI screen capture. It has never lagged for us.

Sorry, you probably need a "real" video card for video encode.

I really tried to make OBS work at 1080p on my 2015 MacBook Pro, but just about anything (even a simple flip the webcam output) causes my fan to spin to maximum and eventually the video lags behind.

The best thing I could do was get something like the Avaya HC020 Webcam. It does a lot of things like zoom, flip, color balance, etc. all in the camera so you're processing as little as possible. At that point, I think I got 720p reliable, but not 1080p. However, my fan was still going full blast.

Eventually, I just gave up and built a Windows 10 desktop machine solely for video. It works great and I don't have a jet engine powering up next to my face when I do video.

If it’s important to be worth the $, get an eGPU

On some Macs (typically Radeon equipped ones) you can enable hardware encoding. I'm not at my machine, but it should read something like "Apple hardware accelerated $FOOBAR"

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