Question / Help Question CPU usage on dedicated stream PC

Belatis

New Member
Hello everyone.

I "rebuild" my dedicated Streaming PC. Hardware is a Dell T20 with a 3.2GHz Xeon 1225v3 and 12GB RAM on Win 10 Pro Version 1704 (first creators update). It uses an avermedia Live Gamer HD lite 1 (HMDI capture card).

With Voicemeter Banana on with VBAN (network audiostream for my mic on my recording PC) and OBS open + Xbox app I have a CPU usage of around 10%.

OBS is version 19.0.3. My video/canvas resolution is 1080 with no downscaling, bicubic 16 samples.

I tested with x264 720p30@2500KBit and 4500KBit. The presets I used were veryfast and faster. On faster my CPU spiked at 100% usage and the stream /recording was choppy at times.

Before I used an RTMP-server solution with nginx and ffmpeg on my streaming PC on Ubuntu and my recording PC (using an Elgato HD60) send a RTMP stream in 1080p30 with 40MBit via Quicksync. There I could stream with 720p30@medium preset IIRC with a bitrate between 2000-2500KBit. Another test was streaming to twitch in 2500KBit in 720p30@veryfast and to youtube in 1080p30@veryfast with 5000KBit.

My question is: Did my Ubuntu setup not use much performance because the Quickync stream from my recording PC being in "h264"? So the "heavy workload" for converting source material into h264 was done by Quicksync? Now my stream PC with Win 10 and Avermedia Live Gamer HD has to use more power for converting to h264 from the capture card?

Is there a website /calculator which can "roughly" tell what kind of cpu power you need for certain resolutions like 720p/900p/1080p?

I hope you understand my question. Thank you in advance.
I will provide a log in the evening.
 

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Boildown

Active Member
There's no rough calculator, as there's too many variables to keep track of.

I'm a bit concerned about you using the integrated GPU instead of a discreet gaming GPU. OBS requires a not-bad GPU while nginx/ffmpeg does not. Yet I'm not sure enough to recommend that you buy one. If you can swap video cards around and put your gaming GPU into your streaming PC, as a test, you could tell for sure.

How sure are you that the performance was good with nginx/ffmpeg? I'm unfamiliar with what kind of logging it does.
 

Belatis

New Member
"How sure are you that the performance was good with nginx/ffmpeg? I'm unfamiliar with what kind of logging it does."

I kept a close eye on HTOP, a task manager on linux. It shows the cpu usage and I monitored my streams on twitch and youtube and looked at the archived streams on those plattforms.

I know that OBS needs some sort of compatible 3D graphicscard. But a better one? I thought it was necessary when using game recording PC, but not just for streaming. I read some recommandations on PCs dedicated to streaming only. My T20 does not come with a 6-/8-Pin power connector so I can't put my R9 290 in there. My only other choice is a GTX 570 but my T20 doesn't have a 6-/8-Pin power connector that the Geforce 570 also needs.
For example an 4790k "should be" ok for streaming in 1080p60 (I can't find the thread...) with an Elgato HD60.

Ok. I think 900p or 720p should be my concern and the presets of faster or medium. I will take a look into the graphicscard theme. Thank you for your input!
 
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Boildown

Active Member
Your GTX 570 is good enough for your streaming PC for OBS's needs. OBS needs a GPU regardless of what you're doing, and the embedded GPU on many Intel chips is kinda borderline because you're stressing the CPU pretty hard. On the Nvidia side, anything like a GTX 550 Ti, 650 Ti, 750, 950, 1050, or better, should be good enough.
 

Belatis

New Member
Sorry. I forgot to write that my T20 does not have a PCIE-Power-connector... I edited my post above. I will try a Geforce 710 and report back.
 

Belatis

New Member
It only has Sata power connectors. OK. I will look for a used rx460/750/950/1050. I don't want to change the PSU in the T20.
Thank you.
 

Belatis

New Member
I still made a test with the Geforce 710 and I have a much better result then before!. Now a can run 720p30 with medium preset like before. But I ordered a 1050 non ti nevertheless. Thank you very much for your recommondation! I will make a test, if the performance gets better with the 1050.
 
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