Question / Help 6 core processor for streaming

[IMSiggy]

Hi all!

This is my first post in these forums and I hope I'm placing my question in the right forum.
I searched Google, I searched this forum for answer, but I don't think I got the answer I wanted.

I would like to ask - "How much CPU power does OBS need for streaming in 1080p@30FPS (3000-5000 kbps)"?

Right now, I'm running at 2500K at stock frequencies and this CPU is completely sufficient for playing (only playing) any game. However, I'd like to stream my games at 1080p@30FPS and that processor (even overclocked to 4.2GHz) is not enough.

I'm playing at 2560x1600, so no capture card will do the trick for me as their input is limited to 1920x1080. So the only solution I can think of is more powerful CPU. I'm particularly interested in 3930K. From the benchmarks it really seems that it's equal with 2500K when it comes to games performance.

Here comes another question - Will the additional two cores of 3930K be enough for OBS (again - streaming at 1080p@30FPS with solid bitrate)? Example: I set the affinity for the game to first 4 cores (8 threads) of 3930K and I set the affinity for the OBS to remaining 2 cores (4 threads). Will this be enough for OBS?

I'd like to keep the CPU at stock.

 

[R1CH]

Most games don't scale beyond two cores, so you'd be better off assigning four cores to OBS or don't bother setting affinity at all. How much CPU power is needed depends a lot on the complexity of your scenes, but a six core Intel CPU should be able to do 1080p30 without much trouble.

 

[IMSiggy]

Thank you for answer R1CH! I'm (not only, but mostly) interested in Crysis 3. According to some info from Crytek, I think that game can utilize more than 4 cores (if they are available). That's why I formed my question in the way I did.

I have to admit that your answer surprised me a bit ("so you'd be better off assigning four cores to OBS or don't bother setting affinity at all") - could it be possible that those two cores are not enough for such streaming?

I'm asking all this because buying 500 EUR CPU just finding out it's not enough would be quite expensive experience :)

 

[Haliinen]

No, your current CPU is fine. I'm on a 2560x1600 monitor as well, so what I do is running the game I'm streaming in windowed, say 1920x1080, then using the downscaler in OBS to downscale to 1280x720 (because honestly, 720p is more than fine for streaming, especially if you're streaming at 60 fps (and it's not a real CPU killer as long as you don't turn to a very slow preset). You could try to run your game in 2560x1440 windowed, then downscale the resolution to 1920x1080 (or 1280x720, I recommend this resolution) with the help of OBS, though keep in mind you'll need to turn down your graphics in game to free up CPU resources and more stuff so OBS can make use of it (since you said you're going to stream Crysis 3). I recommend to keep the preset to very fast because 1080p @ 30 fps requires a pretty good CPU for that kind of encoding.

 

[IMSiggy]

Hi Haliinen, thank you for the answer. But the thing is, that I want to play my games fullscreen at 2560x1600 and stream in 1080p@30FPS. And that's something 2500K can't handle.

 

[Haliinen]

Gotcha, then I doubt a 2500K is going to make it, (unless you overclock it much) or else you will need to turn down the graphics settings that depends on the CPU.

I was just like you before, I really wanted to stream in 1080p @ 30 fps while playing my games in full screen, but then I realized that it was not worth it. It's so much better to keep some space over to say twitch chat so you can interact with your viewers at the same time as you're playing, even though full screen gaming is what almost everyone prefers, it is not optimal for streaming in my opinion. So yeah, another 2 cores and 4 threads for the encoding will certainly help but I'm not sure if it really justifies the money you'll spend.

 

[IMSiggy]

So yeah, another 2 cores and 4 threads for the encoding will certainly help but I'm not sure if it really justifies the money you'll spend.

And this is exactly what I'm interested in. I know those 2 extra cores (4 threads) will help. But I need to know if it will be enough.

 

[Bensam123]

How much those two extra cores are worth is a very good question. That's part of why I've been pushing so much for lan encoding and opencl support. I actually did some lan encoding with pretty promising results for what I hobbled together. It's easy to simply buy a low end video card and plug it into your computer too.

It really depends on how much you value your dollar... I'm pretty sure it'd make a pretty discernible difference. That's essentially like tacking on a extra 50% horsepower... You could OC it on top of it too... Being worth $500 for two more cores compared to $200 is sketchy, but streamers don't have many alternatives to get the performance they want.

I've been debating on selling my 3570k and purchasing a 8350 instead to see how it handles streaming workloads, due to AMD chips seemingly being better at multitasking. Unfortunately there aren't hardware websites that do stream benchmarking of any type. The majority of streamers seem to be Intel crowd too so it's really hard to gather data on this.

 

[Haliinen]

How much those two extra cores are worth is a very good question. That's part of why I've been pushing so much for lan encoding and opencl support. I actually did some lan encoding with pretty promising results for what I hobbled together. It's easy to simply buy a low end video card and plug it into your computer too.

It really depends on how much you value your dollar... I'm pretty sure it'd make a pretty discernible difference. That's essentially like tacking on a extra 50% horsepower... You could OC it on top of it too... Being worth $500 for two more cores compared to $200 is sketchy, but streamers don't have many alternatives to get the performance they want.

I've been debating on selling my 3570k and purchasing a 8350 instead to see how it handles streaming workloads, due to AMD chips seemingly being better at multitasking. Unfortunately there aren't hardware websites that do stream benchmarking of any type. The majority of streamers seem to be Intel crowd too so it's really hard to gather data on this.

The FX-8350 is on par with a 2600K when it comes to x264 encoding, both stock clocked. I believe the FX-8350 is 4.0 GHz on stock while the 2600K is 3.4 GHz on stock, so I guess the 2600K would win here if they were at the same clock speed because of a higher IPC and stuff.

 

[IMSiggy]

How much those two extra cores are worth is a very good question. That's part of why I've been pushing so much for lan encoding and opencl support. I actually did some lan encoding with pretty promising results for what I hobbled together. It's easy to simply buy a low end video card and plug it into your computer too.

Well it depends - either I have hex core CPU and I might be able to stream/record video or I cannot. Regarding lan encoding/opencl support - I'd like to stay away of that direction. I'm sure it has benefits but new problems as well. And I can use 6 cores for other stuff than streaming as well.

 

[Grimio]

I'm not sold on network encoding after thinking about it. Do you intend to send uncompressed data though a gigabit network? If so, then you will pretty much completely saturate or in worst case go over the bandwidth limit.
It doesn't sound like a good thing for live streaming. When encoding a prerecorded vod that doesn't depend on immediate streaming it's a good idea to speed up the encoding time, but in this case... ehhh.
OpenCL encoding is still really bad compared to software or QuickSync. I heard some promising PR spin from AMD that they will improve it, but I still didn't see anything yet.

 

[IMSiggy]

Guys, I appreciate the effort. But please, stay on topic. Is Intel hexa-core CPU enough for streaming at 1080p@30fps? Are 2 separate cores (4 threads) enough for streaming at 1080p@30fps?

 

[Grimio]

Sorry Siggy, I should at least contribute something while blabbering about unrelated stuff.
The thing is, I think no one can give you a yes or no regarding this question. Playing at such a high resolution is fine for a high end system, but when you throw in 1080p live encoding AND a Crysis game into the mix, the only thing you can reliably get is a "maybe".

 

[IMSiggy]

Sorry Siggy, I should at least contribute something while blabbering about unrelated stuff.
The thing is, I think no one can give you a yes or no regarding this question. Playing at such a high resolution is fine for a high end system, but when you throw in 1080p live encoding AND a Crysis game into the mix, the only thing you can reliably get is a "maybe".

Thanks and yes, I completely understand what you mean. I just thought someone here might have the experience with such CPU or that someone from OBS stuff might have some lab test knowledge in this matter.

 

[Grimio]

It's worth asking, for sure. Maybe we get lucky and someone DID test something related :)

 

[Bensam123]

I mentioned a streaming workload which is different from a encoding workload or simply gaming workload. There is a lot more going on in the background.

There is a thread in the suggestion forums concerning lan encoding. It's a great thing and a lot of things that were mentioned were covered there. No, uncompressed frames wouldn't be sent over the network. Only reason not to like it is because you want to cling to ultra expensive hardware.


Siggy this all comes down to a very subjective question and whether or not you want to pull the trigger on something like this. I'm sure you'll have overhead available for streaming at 1080p@30. I almost do with a 3570k, throwing a extra 50% horsepower on top of it would definitely make a difference as I said. How much of a difference depends entirely on how much action is happening on the screen and how much performance you're comfortable with OBS eating.

Hardware websites are barely catching onto the streaming scene, I doubt you'll find anything more then a subjective experience here of someone that upgraded to a hexacore (if that, $500 is a lot to drop on a processor). You can pretty much take the CPU usage of a 3570k and take 75% of that is what you'll end up with.

 

[IMSiggy]

I mentioned a streaming workload which is different from a encoding workload or simply gaming workload. There is a lot more going on in the background.

There is a thread in the suggestion forums concerning lan encoding. It's a great thing and a lot of things that were mentioned were covered there. No, uncompressed frames wouldn't be sent over the network. Only reason not to like it is because you want to cling to ultra expensive hardware.

No, it's not about cling to ultra expensive hardware. I did have a look at the lan encoding thread (viewtopic.php?f=7&t=329&hilit=lan+encoding). I clearly see the advantages of such approach, but right now, there is not really any clean way how to make it work (or maybe I missed something in that thread - if so, please correct me). That's why streaming from one computer still seems like the only solution in my case.

 

[Bensam123]

No, in it's current form it's not capable of being mainstream. I meant I'm pushing it as in other people will take a look at it's potential and ask for it as a feature so it'll hopefully move up the development list as something that's requested. So people like you and I wont have to purchase $500 processors.