CPU for local recording

[Giuseppe.B]

Hi there! :)

I'm not a gamer but a simple content producer.

I need to record remote video interviews I do with other participants on Zoom (video conference) + my own camera (a Sony A6000 mirrorless camera captured through and HDMI capture card) and I edit the video in real time, with OBS. By "editing" I mean switching from a scene to another.

My current laptop is not powerful enough (CPU Intel i7-6560U with Intel Iris 540 as integrated GPU) and the final video is completely choppy, like one image every 2 seconds... :(

I'd like to have a very high quality final video, same quality if I was recording directly from my camera into the internal SD card of the cam.

Just 1080p @ 60 FPS would be enough, with no quality loss.

Since I'm not a gamer, I guess (?) I don't need a powerful GPU (graphic card) but I need a power CPU in order to encode / record the video in real time. So, I guess I must use x264 to encode. Is that correct ?

Since I'm not streaming but simply doing a local recording and since I'm looking for a top quality recording, do you think the AMD Ryzen 5 3600 (6 cores / 12 threads) on a GIGABYTE B550M S2H motherboard is enough for my need or I need more CPU power ? Is that correct that in my case I can get a very old / slow graphic card ?

Thank you !

 

[qhobbes]

If you have the option for QuickSync/QSV as an encoder, try that with:
Rate Control: CRF/CQP
CRF/CQ: 0
Keyframe: 0
Profile: High
Usage: Quality

 

[Lawrence_SoCal]

Why 60fps for an interview? you planning a slow-motion replay?
I'd think you'll significantly lower system impact if you cut your frame rate in 1/2 and go with normal 30fps

As for GPU offload, my research pointed to using the lowest end Turing based NVENC, which is in the GTX 1650 Super, which isn't that expensive (under $200). I just bought a 8c/16t with a GTX 1660 Super (only because this vendor didn't offer the 1650S) and I'm expecting many years of use (at least 5, and I will have auto voltage regulating UPS/battery power, and I know how to properly manage machine, so that is very doable). My new system is very overpowered for the simple type streaming you are referring to... though it does depend on whether you are trying to get fancy/sophisticated with OBS filters and effects which can have a significant CPU impact to process (depending on exact usage).

so for simple OBS usage, you might be able to get your current system to work. I had a with i5-6300HQ @ 2.3GHz (4c/4t) Fall 2015 release that wasn't enough for bouncing back and forth from live USB webcam and pre-recorded 4K video, and a lower understanding than I have now of OBS operations. It wasn't worth it to me/us, and we got a new PC. But I could get that 5+ yr old laptop to work with OBS. You have a low-power (U) CPU, so... not sure, but with low demand settings, maybe

 

[Giuseppe.B]

If you have the option for QuickSync/QSV as an encoder, try that with:

Hi qhobbes !

Thank you for your answer.

I do not have choosen a graphic card (I'm thinking now about what PC to buy) so does the QuickSync/QSV depends on the graphic card ?

Since a "just" need powe to encode / record (locally) I was thinking a need a powerful CPU and a cheap / second hand low cost graphic card. Is that a bad idea ?

 

[Giuseppe.B]

Hello Lawrence_SoCal and thank you for your answer !

Why 60fps for an interview? you planning a slow-motion replay?
I'd think you'll significantly lower system impact if you cut your frame rate in 1/2 and go with normal 30fps

You are right, actually 25fps would be just fine. No no, no need for slow motion :) :)

Since I'm recording with my mirroless camera (the HDMI clean output is sent to the capure card wich transofm it into a USB cam) I was thinking if the camera sends 60fps the quality will be better but you are right, the final video in 25fps would be completely enough !

As for GPU offload, my research pointed to using the lowest end Turing based NVENC, which is in the GTX 1650 Super, which isn't that expensive (under $200). I just bought a 8c/16t with a GTX 1660 Super (only because this vendor didn't offer the 1650S) and I'm expecting many years of use (at least 5, and I will have auto voltage regulating UPS/battery power, and I know how to properly manage machine, so that is very doable). My new system is very overpowered for the simple type streaming you are referring to... though it does depend on whether you are trying to get fancy/sophisticated with OBS filters and effects which can have a significant CPU impact to process (depending on exact usage).

Actually no, I don't need any fancy/sophisticated effect. Just fasic fader between a scene an another.

I have Zoom running the videocall and taking the picture of the other person from the Zoom windows + another source is my Sony camery (USB through the HDMI capture card) and sometime we show just the other person, somtime just me, sometime both, etc. These king of simple transitions ;)

I was thinking I don't need a powerful graphic card at all and rely on the CPU (x264) only but maybe I'm wrong ?

so for simple OBS usage, you might be able to get your current system to work. I had a with i5-6300HQ @ 2.3GHz (4c/4t) Fall 2015 release that wasn't enough for bouncing back and forth from live USB webcam and pre-recorded 4K video, and a lower understanding than I have now of OBS operations. It wasn't worth it to me/us, and we got a new PC. But I could get that 5+ yr old laptop to work with OBS. You have a low-power (U) CPU, so... not sure, but with low demand settings, maybe

Yes, right now I have a low-power CPU (Intel i7-10710U) and it's not capable to record loclally a decent video.

Actually, even before starting recording : when I put the USB camera (which is the Sony mirroless camera) in full screen and I move quickly, the image (preview) is a bit choppy. And when I start recording (even a simple screencast, without ahving other programs open) the final video is useless, kinda 1fps or even 1 frame every 3 seconds ;)

 

[Lawrence_SoCal]

Quicksync is an Intel encoding option (so using CPU).. ie recommended to hopefully optimize the use of the laptop that you have

as for new system... you could go more powerful PC and do all encoding in CPU, or you could more balanced and use GPU encode offload. Pro's and Con's to each approach. Considering you were using a laptop, the benefit of an all CPU approach would be getting a small form factor PC

 

[Giuseppe.B]

Quicksync is an Intel encoding option (so using CPU).. ie recommended to hopefully optimize the use of the laptop that you have

Oh, OK, I see. That's for my current situation. I will try, thank you !

as for new system... you could go more powerful PC and do all encoding in CPU, or you could more balanced and use GPU encode offload. Pro's and Con's to each approach. Considering you were using a laptop, the benefit of an all CPU approach would be getting a small form factor PC

When we use GPU encode (for enxample with NVENC) this means the GPU / graphic card does all the job and the CPU does "nothing" so to say ? But I can imagine even a 200$ graphic card has not the compute power of an Ryzen 5 with 6 cores, I am right ? I guess the final quality with CPU (x264) encoding is better if it's the GPU (NVENC) that does the job... But I'm maybe wrong !

Actually, if I change PC; I will go for a desktop PC with a small tower (mATX) or a small form PC with mini ITX but I'd like a silent solution...

 

[Lawrence_SoCal]

You are right, actually 25fps would be just fine. No no, no need for slow motion :) :)

Actually, think about your target watching environments. Broadcast TV would use 24/25fps. But most streaming platforms, will use 30fps

Since I'm recording with my mirroless camera (the HDMI clean output is sent to the capure card wich transofm it into a USB cam) I was thinking if the camera sends 60fps the quality will be better but you are right, the final video in 25fps would be completely enough !

you'll have to test. first a clean multiple (vs a fraction) of the camera video rate is desired. If your capture card is USB 3, and you don't overload your USB root hub, then 60fps may be fine. Otherwise, avoid the data challenge and set the camera to use 30fps [but don't take my word for it... test. and maybe research your exact model camera and specific capture card for details/recommendation]

Zoom adds its own complexity, and CPU requirements. Realize if you Zoom participant can see you in Zoom, then your PC is encoding video twice (once in Zoom, once for OBS.. maybe, depends on your setup). And beware audio loops

Yes, right now I have a low-power CPU (Intel i7-10710U) and it's not capable to record loclally a decent video.

CPU could be an issue. Not as likely, but disk throughput (video recorded file) could also be issue if that older system has a HDD vs SSD

Also, be aware that OBS Studio Mode renders video twice, so something to avoid with under-powered system (ie don't be in Studio Mode.. default button in lower right of PBS panel by start streaming/recording/settings)

And there are lower CPU impacting options than Zoom for bringing a guest into OBS (like OBS.ninja and others... each has its own Pro's/Con's) IF Zoom itself works, and for guest comfort using a tool they likely already have, you may want to learn more about Zoom and use its operations/options, and recording feature instead? basically... an on-point recommendation would depend on other details not in this thread at this point.

 

[Giuseppe.B]

Yes, right now I have a low-power CPU (Intel i7-10710U) and it's not capable to record loclally a decent video.

My bad : I don't have such I CPU. Mine is an Intel i7-6560U (not 10th gen)

 

[Giuseppe.B]

Thank you very much for all these hints, Lawrence_SoCa !!

 

[Lawrence_SoCal]

When we use GPU encode (for enxample with NVENC) this means the GPU / graphic card does all the job and the CPU does "nothing" so to say ? But I can imagine even a 200$ graphic card has not the compute power of an Ryzen 5 with 6 cores, I am right ? I guess the final quality with CPU (x264) encoding is better if it's the GPU (NVENC) that does the job... But I'm maybe wrong !

Actually, if I change PC; I will go for a desktop PC with a small tower (mATX) or a small form PC with mini ITX but I'd like a silent solution...

No, GPU encode offload takes part of the overall process and offloads it, but there is still plenty of work for the CPU and pairing a really low end CPU with an appropriate NVENC capable CPU is a bad idea (really limiting). What using NVENC will do, from what I gather, and their are others who know way more than I do, is allow a heavily utilized CPU (as is the case when gaming) and not require a much more expensive option (the increase price curve at the upper end).. so, offloading video encoding to a $200 GPU vs spending $500 more dollars on an even faster is a good trade-off...

When it comes to a small form factor silent PC option... be aware, you will need enough CPU power, and you may have fan noise to deal with. and depending on setup, in a few years time, if new software/etc demands more of PC, you may not be able to 'upgrade' by adding a decent NVENC GPU (both physical space, and power supply). The GTX 1650 Super requires its own power connection (can't be powered from PCIe bus)

if you are going the Do-it-yourself build approach, I'd personally recommend finding a case /motherboard that would accommodate a GTX 1650 Super (with some power to spare), and then try without it. Realistically, a decent Ryzen 3600 should be fine, and then you have a relatively inexpensive upgrade path. Assuming a year or two before considering a GPU upgrade, I'd probably spec a mini RTX 3060 in terms of power (mini doesn't exist yet, but should be in that timeframe, and compare RTX 2060 vs mini RTX 2060 for power delta for planning purposes).

 

[Giuseppe.B]

Once again @Lawrence_SoCal and @qhobbes !

With your tips I managed to record something almost "decent" with my NUC (with laptop components) that is an Intel i3-3217U (notice the "U) and its integrated Intel HD 4000 graphic GPU.

Of course, NOT with x264 (CPU becomes overloded) but with FFMEPG VAAPI as encoder I can create some videos. Under my Linux setup (wrong forum, I know...) I do NOT have the Quick Sync but FFMEPG VAAPI with H.264 it's quite OK.

I need to test / study all these things again. Just posting this to thank you both and if this may help someone else.

I will probably better config / hardware but I need to understand better the role of CPU and GPU in all these. Thank you again @Lawrence_SoCal for what you shared with me.

Cheers ! :)