Need help building a machine for H.264 encoding

[N-Gen]

Hey everyone, a few days ago I had an idea for a build for H.264 encoding, mainly for streaming but possibly used for other things as well considering the hardware.

I will outline the build and what I'm looking for further below.

I'll try to keep it as short as possible. The current setup is single PC, consisting of the specs in my profile, to recap here TR 1950X, 32GB RAM, 1080 Ti. The issue is I have to cap my frame rate to 60. Having 60hz monitors this is not a big deal but I have to limit it every single time because OBS/Streamlabs OBS will use some GPU to encode the image before sending it over to the CPU. I'm using the native monitor 2560x1440 canvas size and rescaling it to 900p. Having it rescaled to 720p uses about 8% of the GPU anf 900p about 11%. If I do 1080p this will shoot up to around 18%.

In some games this isn't an issue, BF1 on 1440p Ultra with VSync on leaves lot a of space for encoding but if I fire up AC: Origins, even at 60fps the applications are fighting each other for the GPU power ending up in lost frames on the encoder and frame lag in game. This is purely a GPU issue since the CPU pulls 900p60 on the h.264 slow profile with about 25% usage. The idea when streaming, contrary to what we do when trying to avoid GPU bottlenecks, is not to let the game use 100% GPU. If I were playing in 1080p this would probably not be an issue at all (which is why I see no complaints by people playing at this resolution) but I don't want to downgrade to a 1080p monitor nor do I want to have my 1080 Ti in there being restricted.

My idea was to build a separate streaming machine, I do already have a capture card so we don't have to go into the merit of transferring the image. Before anyone mentions NDI, yes I know it exists. The problem with NDI is you still need OBS open on the sender side which pretty much means the GPU encoding issue is still present.

On to the build, I have many components from decommissioned machines I can use because I hoard parts since I find it difficult to sell them off. I'm trying to stay on the DDR3 side of things since I have a lot of spare sticks and wouldn't like to invest in DDR4 at the moment. The idea is to re-use most of my idle components and spend as least as I can to get the build done. Now my problem is, if this ends up being worse encoding than my 1950X is doing it will end up being a total waste, even though I could use the machine for VMs or something.

My list of available components as follows:

• 44GB of RAM, split into 10 x 4GB sticks and 2 x 2GB sticks, different manufacturers, different speeds ranging from 1333Mhz to 2133MHz
• A couple of Silicon Power 120GB SSDs, don't need much storage
• NZXT Hale82 850W Bronze PSU
• A few spare GPUs, my spares are all AMD but I think I'll go for the HD7850 1GB, if I need to go beefier I have a 290 but I doubt I'll need it and would rather keep the temps/power draw lower
• Some cases available but this isn't an issue

And this leaves me with a CPU and motherboard problem. Since I have DDR3 available and Xeons are available I was thinking of going dual 2011. I would be willing to buy a new Chinese X79 board with dual sockets however they seem to all have only 4 DIMM slots which is ok, I don't need more than 16GB to encode but if I wanted to use the machine for VMs later that would leave me a bit limited, so I'm stuck without board options right now. It should additionally have PCIE x16 slots for capture cards (currently only 1 internal) and a good number of USB ports (let's say 6+) for the peripherals to be added, keyboard, mouse, webcam, stream decks and so on.

As for CPUs, I set my eyes on 2 models, one being the E5-2680 v2 2.8Ghz 10c/20t, the other E5-2650 v2 2.6GHz 8c/16t. I was going to go with a single CPU at first and see how that goes and maybe later add the second one. What worries me is how will h264 scale across the threads? I know a dual 2650 v2 setup will give me 16c/32t just as my 1950X gives me but there's a clock difference between 2.6GHz and 4GHz (not sure of Ivy Bridge EP IPC).

Any opinions are greatly appreciated, I feel a bit lost since if it ends up not being worth doing I would have rather just waited and built separate gaming PC and use my current machine for the encoding.

Additionally, I never owned a dual socket system to I thought it would be cool to have one to play around with but it also means I don't know much about them in practice. Besides, I'm always trying to find an excuse to build something.

 

[DeathtoGnomes]

You are barely scratching the surface of the 1950X, I'd suggest adding a 2nd or even 3rd GPU before building another PC. You can set core affinity for a lot of programs at one time. Your 32gb ram should be enough for what you want to do, but dont rule out upgrading to 64gb, test and see what happens with 32GB.

I dont own the stream deck from Elgato but i hear good things about it when using multiple PCs. I watch several streamers on twitch and none of them come even close to your current set up, several had intel setups and jumped over to a ryzen build. TBH, I wouldnt waste your money on dual Xeons for streaming where a medium budget build would do just fine for your purposes.

 

[N-Gen]

The Stream Deck is so amazing that I ordered as second one, and that's for a single PC setup. I use them for everything and they're massive productivity boosters.

But as I said, it's not an issue with the CPU, it's been a pleasure to work with and has lots of headroom still there. With games running and encoding CPU usage is still under 50%. RAM I'm fine with being at 32GB even for After Effects. The quality I output is praised by people who come to watch the stream and I try not to spare anything when it comes to that quality.

The issue is the GPU usage which multiple GPUs won't really help with. I only though about dual Xeons because for under €600 I should be able to build a machine with 20c/40t to offload all the encoding on.

 

[GorbazTheDragon]

Why not use the TR with some second rate GPU for encoding rig and get a fast clocked intel for playing on then? If you really want to use a 2 system setup, that is my first choice.

I am not sure why OBS is using a lot of GPU resources, I would suggest plugging in a second card if you have it and running a second monitor off that card with OBS on that monitor and seeing whether that GPU starts seeing usage from OBS.

And first of really I would suggest troubleshooting why OBS is using those resources in the first place because it doesn't in my experience...

 

[FordGT90Concept]

If you don't need OBS features, ShadowPlay/ReLive are better performance wise. With ReLive, I can't even tell I'm recording because the Video Coding Engine is doing 99% of the work.

 

[GorbazTheDragon]

I use OBS with NVenc on my laptop, anything that I can normally play is equally playable with OBS recording or streaming.

On my older laptop (the one below) I also used OBS but with quicksync, that was somewhat slower, but it wasn't really that bad either although back then I hadn't figured out many of the tricks with OBS yet.

 

[N-Gen]

Why not use the TR with some second rate GPU for encoding rig and get a fast clocked intel for playing on then? If you really want to use a 2 system setup, that is my first choice.

Because I built the TR machine for my editing workflows and buying a new CPU would mean new RAM and a new board which would end up being just as expensive.

I am not sure why OBS is using a lot of GPU resources, I would suggest plugging in a second card if you have it and running a second monitor off that card with OBS on that monitor and seeing whether that GPU starts seeing usage from OBS.

OBS always uses GPU power for compositing and plugging a second card makes it worse. This is mentioned in the OBS forums. Not only that, I have tested it. I dropped a 1060 6GB alongside the 1080 Ti and ran OBS on the 1060. Because the image needs to be transferred between cards, GPU usage spikes to ~50% of the 1080 Ti while it stays below 5% on the 1060 because it has absolutely 0 compositing to do.

And first of really I would suggest troubleshooting why OBS is using those resources in the first place because it doesn't in my experience...

As per the reply to the quote above, it's normal behaviour and becomes more evident the larger the resolution streamed/recorded is.

This is why everyone knowledgeable enough with OBS will tell you always limit your game frame rate and not let the game eat up all the frames it wants. On larger resolutions this means even less frames.

If you don't need OBS features, ShadowPlay/ReLive are better performance wise. With ReLive, I can't even tell I'm recording because the Video Coding Engine is doing 99% of the work.

I do need OBS features though so I'm a bit stuck. Even if I didn't need OBS I wouldn't use the GPU encoders, they've saved me in the past when I had to run a backup machine but CPU encoding delivers better results.

I use OBS with NVenc on my laptop, anything that I can normally play is equally playable with OBS recording or streaming.

Same thing, won't remove the GPU usage used for compositing. Regardless of the encoder run, the compositing is still done on the GPU.

On 1080p, which is what the majority people have at their homes a GPU can deliver more frames than it would on 1440p, this we know. But this also means that the impact on the GPU, if a part of it is used for compositing, is even greater in game.

At this point I think I should take a few screenshots later today and post them. But as a starter this is pretty much what I'm talking about.

 

[DeathtoGnomes]

While i suspect OBS is not using the 2nd card for compositing, if at all you dont have it set up right. We're not suggesting SLi, you set affinity for cards just like you would CPUs. A 2nd card also mean you can offload PhysX to it which can eat alot of GPU depending on the game.

In the end, its up to you, I am of the opinion that if you absolutely must have a 2nd system here, a single CPU system will work just as effectively for your needs. There is also electricity use and its bill to consider.

 

[N-Gen]

While i suspect OBS is not using the 2nd card for compositing, if at all you dont have it set up right. We're not suggesting SLi, you set affinity for cards just like you would CPUs. A 2nd card also mean you can offload PhysX to it which can eat alot of GPU depending on the game.

I didn't SLI for my test, I've ran 3 crossfire setups during the last 7 years so I'm quite familiar with the setups. The 1060 was run independently from the 1080 Ti. I could have added any of my AMD gpus but it would have been a bit of driver mess I don't want to go through again.

It's not a matter of an incorrect setup, in order for OBS to pick up the game it still has to be sent from the 1080 Ti, which is rendering the game, to the 1060, which has to do the compositing. The overhead is so big that it ends up being worse, as mentioned by one of their mods here.

 

[DeathtoGnomes]

have you posted on OBS forums about the problem you're having with dual cards? I see some laptops with dual cards work well and others dont. Getting back to the question of building another PC, sell all your old parts and build a Ryzen system (you wont regret it) for OBS, use the 290 or buy a 580 for around $250.