Question / Help Ryzen 3700X can't handle 900p@60 x264 slow preset?

[Rocha9999]

Hello guys.

I recently bought a whole new system, and I have a question: is it normal that a Ryzen 3700X not being able to handle 900p@60 x264 slow preset?

When I try to stream in 720p@60 x264 slow preset, it goes fine, no frame skippings. But when I try 1600x900 or 1920x1080, I get many skipped frames message in the Stats window, the "Skipped frames due to encoding lag", but CPU usage is not reaching not even 30% usage, according to the OBS Stats window. Very strange.

I have a very capable M.2 SSD (signature for full PC specs), so I don't think it's the issue.

I tried to record locally, same thing happens.

In summary:

720p@60 x264 slow preset = fine
900p@60 x264 slow preset = skipped frames due to encoding lag
1080p@60 x264 slow preset = skipped frames due to encoding lag
1080p@60 x264 medium preset = fine

None of the above configuration reach 30% CPU usage.

Is it a CPU limitation? Twitch limitation? Or OBS limitation?

 

[Narcogen]

Most likely a limit of how many threads FFMpeg can utilize for encoding. Your CPU has plenty of threads left over, but there's only so many that can be practically used for encoding. So the CPU utilization graph is not a complete metric for figuring out how slow a preset a CPU can use.

 

[carlmmii]

What you're seeing is correct for your CPU. I would not trust the OBS cpu usage report -- you'll find a much more telling view using Task Manager's performance tab.

The 3700x cannot realistically do slow on anything above 720p60. You would need to jump up to the 3900x if you want that, and even then you'll encounter the occasional bit of encoding lag, even though it doesn't ever go above 70%.

EposVox has a really good set of comparison videos specifically talking about the Ryzen 3000 series encoding capabilities for OBS, if you want to look those up.

 

[Rocha9999]

Thanks for the responses, guys.

I kinda managed it to stream at 1080p@60 slow preset by adding the x264 option "threads=16". But it has peaks of 80% CPU usage. Not practical when u have other things to worry about like webcams, overlays etc etc.

I'll stream at 720p@60 slow for now, because from my tests and watching other people's tests, the 6k Twitch max bitrate limitation really doesn't make 1080p streaming worth it. It looks uglier than 720p@60 at that bitrate.

 

[SanityKnows]

Just curious if your 3700x is in a dedicated streaming pc or you gaming on it aswell ? I just finished building my dedicated rig with a 3700x and i was testing NDI yesterday and it does an absolutely amazing job of 720p 60fps Medium with 6k bitrate. Didn't have time to test anything else. I've just woke up at the time of writing this message so after my coffee ill be doing some more testing to see What it's capable of with my particular setup and bios settings ect and ill post back. Also remember that no chip is created equal. (silicone lottery) as they say. I'm still in the process of making my own alerts in After effects so ill throw them in as well to strain it as much as possible

 

[carlmmii]

I don't have personal experience with the 3700x, but I have been using a 3600, 3900x, and now a 3950x. Interpolate as necessary for 3700x, or go see EposVox's breakdown/review (seriously, he goes through extensive testing).

As you say, not all chips are created equal, but here's my current take on chip capabilities based on my rigs (3600 and 3950x cooled w/ Kraken x72, 3900x cooled w/ Corsair H110i, all with 3600mhz ram).

For dedicated streaming, the 3600 is easily able to handle 720p60 medium at ~40% usage. Slow is out of the question. 1080p60 is "possible", but you run into the very limits of what this cpu is able to do -- 900p60 medium would be a more realistic upper limit of where I would trust the 3600. I would imagine the 3700x would have a much better time with the extra 2 core headroom.

For comparison, the 3900x will chew through 1080p60 slow with ~60-70% usage, but it will still encounter encoding lag. Slow really isn't meant to be used as a realtime encoding preset. Because of this, even on the 3950x I've just come to accept that the medium preset is honestly the best preset you can use, just because of the unavoidable encoding lag and pretty much imperceptible quality improvement.

Unfortunately I can't speak to the capabilities of anything other than the 3900x for gaming+encoding. On that front... I can't be more pleased. Based on what I've experienced so far, there's actually no reason for the 3950x over 3900x for streaming unless you're really trying to get that slow preset.

 

[SanityKnows]

Yeah i think medium is where it's at anyway tbh, AMD have really impressed me. Can't wait to do some more testing though.

 

[Rocha9999]

Just curious if your 3700x is in a dedicated streaming pc or you gaming on it aswell ? I just finished building my dedicated rig with a 3700x and i was testing NDI yesterday and it does an absolutely amazing job of 720p 60fps Medium with 6k bitrate. Didn't have time to test anything else. I've just woke up at the time of writing this message so after my coffee ill be doing some more testing to see What it's capable of with my particular setup and bios settings ect and ill post back. Also remember that no chip is created equal. (silicone lottery) as they say. I'm still in the process of making my own alerts in After effects so ill throw them in as well to strain it as much as possible

I was testing with games running on same PC, but I plan to use a capture card and stream PS4/PS5 games too, so I think it should be less stressful to the CPU, allowing 1080p@60 slow preset with occasional encoding lags.

All in all, I think 1080p@60 with 6000 bitrate is not worth it, no matter what preset. Maybe if Twitch allowed normal/new streamers to use 8000 bitrate like they do with partners etc, would be a bit better but honestly 1080p@60 can only look good starting at 10000 in my perception.

 

[SanityKnows]

I was testing with games running on same PC, but I plan to use a capture card and stream PS4/PS5 games too, so I think it should be less stressful to the CPU, allowing 1080p@60 slow preset with occasional encoding lags.

All in all, I think 1080p@60 with 6000 bitrate is not worth it, no matter what preset. Maybe if Twitch allowed normal/new streamers to use 8000 bitrate like they do with partners etc, would be a bit better but honestly 1080p@60 can only look good starting at 10000 in my perception.

Yeah i fully agree, Honestly id prefer watching a clean 720p over a messy 1080p anyday