Question / Help Low CPU Usage using Ryzen 1700x

[RBGTheJackal]

I've been having issues with OBS after upgrading from a i7-4790k to a Ryzen 1700x using x264 I'm noticing when streaming to twitch it'll use at MAX 4.2% of my CPU and i'm unable to figure out why so little of my CPU is being used. I'm streaming at 720p 60fps and will hit 60 with some dips to the 55 range. Over time i'll notice it drop lower and lower towards 28fps-48fps with no changes to my settings just wondering if theres something i'm doing wrong causing OBS to not fully use my CPU.
PC Specs:
Ryzen 1700x OC to 4.0GHz
AsRock x370 ITX Gaming
MSI GTX 1070 Aero
Patriot 2x8 16gb DDR4 @ 3200MHz
Internet speeds 150Mbps Down / 25 Mbps Up

Let me know if there is any additional details I'm missing.

 

[SeeOHZeeVT]

The CPU usage is low because you're using the ultrafast preset on x264, which this setting is not intended for streaming. Second, you're probably hitting a GPU bottleneck when playing PUBG and OBS needs spare GPU power to perform well. Cap the in-game FPS to something realistic to reduce GPU usage for OBS to render well.

 

[BK-Morpheus]

Yep ,what OG See OH Zee said.
My 1700x@3.8Ghz 1.125V + GTX1070 are running fine with OBS+PUBG.
On 1440p with low settings (only Textures and Antialiasing @high) the CPU will become the bottleneck in PUBG, even before the GTX1070 is limiting (hard to see the limit, as the Ryzen is not showing high usage, but it is limiting the max fps in PUBG, because the GPU is not utilized much).

As PUBG is not using many cores, I can use x264 medium preset with 720p/30fps streaming or fast with 720p/60fps.