This is the primary a part of an investigation into sport streaming, a subject that we have been requested on earlier than — notably after we assessment CPUs — however that has purposely been ignored as a result of it’s fairly complicated to discover all of the nitty gritty particulars of streaming together with all the things else in these opinions.

In the following weeks we’ll dedicate a few articles to sport streaming and offer you a definitive reply on what kind of setup is the most effective, and what high quality settings take advantage of sense to make use of. Today’s investigation is concentrated on streaming high quality settings, we wish to discover out what encoding settings ship the most effective stability between high quality and efficiency, and the way every of the assorted common encoding modes differs when it comes to outcomes.

One of the important thing issues we wish to determine first: whether or not software program encoding on the CPU, or {hardware} accelerated encoding on the GPU is the higher strategy…

A little bit of backstory on our take a look at platform earlier than we get into the outcomes… one of many key issues we wish to determine first, is whether or not software program encoding on the CPU, or {hardware} accelerated encoding on the GPU is the higher strategy. This is basically one of many key battles, as a result of if GPU encoding is the way in which to go, what CPU you want for streaming turns into largely irrelevant, whereas if CPU encoding is best, naturally your alternative of processor turns into a significant factor within the degree of high quality, not simply when it comes to consistency of streaming, however sport efficiency in your finish.

Over the previous couple of months particularly, GPU encoding has grow to be extra fascinating as a result of Nvidia up to date their {hardware} encoding engine of their new GPU structure, Turing.

Game Streaming Investigation: Which Quality Settings Are Best?

While a number of the main target went into enhancing HEVC compatibility and efficiency, which isn’t actually related for sport streaming for the time being, Turing’s new engine can be presupposed to carry 15% higher H.264 high quality in comparison with the older engine in Pascal (GTX 10 collection). So that’s one thing we’ll look into, and see how Turing stacks up towards x264 software program encoding.

On the GPU aspect, we’ll be utilizing the RTX 2080 for Turing encoding, a Titan X Pascal for Pascal encoding, and we’ll additionally see how AMD stacks up with Vega 64.

The second a part of the investigation includes software program encoding with x264, utilizing quite a lot of presets. We’re going to depart a CPU comparability with software program encoding for a separate article, on this one we’re extra excited by how every preset impacts efficiency and high quality.

Game Streaming Investigation: Which Quality Settings Are Best?

All testing was achieved with the Core i7-8700Ok overclocked to 4.9 GHz and 16 GB of DDR4-3000 reminiscence, which is our present advisable platform for high-end gaming. In the long run we’ll see how the 9900Ok fares together with AMD Ryzen CPUs.

For capturing this footage we’re utilizing the newest model of OBS, set to document at 1080p 60 FPS with a relentless bitrate of 6000 kbps. These are the utmost advisable high quality settings for Twitch, should you had been simply recording gameplay for different functions we’d suggest utilizing a better bitrate, however for streaming to Twitch you’ll must hold it to six Mbps or decrease until you’re a Partner.

We’re testing with two video games right here, we’ve got Assassin’s Creed Odyssey which is a extremely GPU and CPU demanding title, one thing that CPU encoding struggles with; and Forza Horizon 4, which is much less CPU demanding however a quick paced title that low bitrate encoding can have points with. Both titles current a little bit of a worse case situation for sport streaming, however in numerous and distinctive methods.

We’ll begin with GPU encoding, as a result of that is one thing that has been recognized to be moderately horrible for a very long time now. The key little bit of curiosity right here is to see how Turing has managed to enhance issues in comparison with previous GPU encoding choices, which had been just about unusable subsequent to CPU encoding choices.

For Nvidia playing cards we used the NVENC choice in OBS, and set it to make use of the High Quality preset at 6 Mbps. There are just a few different preset choices however High Quality produces, because the title suggests, the very best high quality output. For AMD’s Vega 64 we tried a variety of encoding choices, each when it comes to preset and bitrate, with out a lot luck as you’ll see within the comparisons shortly.

Game Streaming Investigation: Which Quality Settings Are Best?

Putting Turing and Pascal’s NVENC implementations aspect by aspect, there actually isn’t that a lot of a distinction at 6 Mbps. Both endure from critical macroblocking results, and basically there’s a full lack of element to the picture. In Forza Horizon Four particularly, blocking may be very noticeable on the highway and appears horrible. Turing’s encoder is probably a bit of sharper and in some conditions is much less blocky, however actually each are rubbish and if you wish to stream video games, this isn’t the type of high quality that can impress your viewers.

Game Streaming Investigation: Which Quality Settings Are Best?

AMD’s encoder is even worse in that when your GPU utilization is up close to 100%, the encoder utterly craps its dacks and may’t render greater than about 1 body per second, which wasn’t a difficulty with the Nvidia playing cards.

I used to be in a position to get the encoder working with a body limiter enabled, which introduced GPU utilization right down to round 60% in Forza Horizon 4, however even with the ‘Quality’ encoding preset, the standard Vega 64 produced was worse than with even Nvidia’s Pascal playing cards.

Game Streaming Investigation: Which Quality Settings Are Best?

With AMD’s encoder out of the query proper from the start, let’s have a look at how Nvidia’s NVENC compares to software program x264 encoded on the CPU. In the slower shifting Assassin’s Creed Odyssey benchmark, NVENC even utilizing the High Quality preset is noticeably worse than x264’s veryfast preset, notably for positive element, even when each are restricted to simply 6 Mbps.

Veryfast x264 isn’t wonderful by any stretch, however the degree of blocking and the dearth of element to Turing’s NVENC implementation is horrible as compared.

Game Streaming Investigation: Which Quality Settings Are Best?

In the quicker shifting Forza Horizon Four benchmark, Turing’s NVENC does outperform x264 veryfast in some areas, NVENC once more in all probability has barely worse blocking however veryfast actually struggles with shifting positive element. With this degree of movement, NVENC is roughly equal to x264’s “faster” preset. There is little question, nonetheless, that x264’s “fast” preset is considerably higher than NVENC in quick movement, and utterly smokes it when there’s sluggish or no movement.

Game Streaming Investigation: Which Quality Settings Are Best?

These outcomes are maybe a bit of stunning contemplating Nvidia claims their new Turing NVENC engine for H.264 encoding is across the mark of x264 quick encoding and even barely higher at 6000 Kbps for 1080p 60 FPS streaming. But from what I noticed, particularly in Assassin’s Creed Odyssey, software program encoding was significantly better.

Game Streaming Investigation: Which Quality Settings Are Best?

When trying purely at software program x264 encoding presets, there are noticeable variations between every of veryfast, quicker, quick and medium. In the slower shifting Assassin’s Creed Odyssey – and ignoring the clear efficiency points with some presets for now – veryfast and quicker don’t ship an awesome degree of high quality, with a number of smearing, blocking in some areas, and an absence of positive element notably for objects in movement.

These two presets actually must be reserved only for those who wish to stream casually, as a result of the presentation when capped to six Mbps isn’t nice.

Game Streaming Investigation: Which Quality Settings Are Best?

The quick preset is the minimal I’d think about using for a top quality sport stream, notably should you worth picture high quality in your viewers. It offers a noticeable high quality soar over quicker, to the purpose the place blurred positive element now has definition.

Medium is a noticeable enchancment once more, however the hole between quick and medium is smaller than the hole between quicker and quick. And as we’ll see in a second, good luck utilizing the medium preset on the identical system the sport is working on. I did additionally try the sluggish preset however at this level we’re into diminishing returns for an enormous efficiency hit.

Game Streaming Investigation: Which Quality Settings Are Best?

For quicker movement in Forza Horizon 4, once more I’d utterly dismiss the veryfast preset instantly as a result of it’s worse than NVENC for this kind of content material. Unfortunately the tight bitrate restrict of 6000 kbps prevents any preset from doing true justice to the supply materials, however as soon as once more medium will get the closest and offers an enchancment over quick.

The quicker preset seems horrible so once more I’d recommend quick as absolutely the naked minimal for this kind of content material, actually I’d suggest medium at a better bitrate however hey, Twitch has set the restrict to six Mbps so it’s principally the most effective we are able to do.

Performance

But picture high quality is just one a part of the equation, after all, the opposite is efficiency, and if you’re streaming your gameplay from the exact same pc you might be taking part in on, it’s necessary that each your gameplay expertise and the efficiency of the stream are sufficient.

We’ll begin right here by GPU encoding and see how that impacts efficiency…

Game Streaming Investigation: Which Quality Settings Are Best?

Game Streaming Investigation: Which Quality Settings Are Best?

Enabling both Pascal or Turing’s NVENC engine impacts the body fee of the sport by round 10 to 20% relying on the sport, in different phrases, you’ll see a 10 to 20% drop to border fee when capturing footage utilizing NVENC, in comparison with not capturing the sport in any respect. The extra GPU restricted the sport is, the extra of an affect NVENC could have, which is why Forza Horizon Four is impacted extra closely than the heavy CPU person in Assassin’s Creed Odyssey.

The excellent news, although, is whilst you’ll be working the sport at a decrease framerate whereas NVENC is working, the stream itself could have excellent efficiency with no dropped frames, even when the sport is utilizing 100% of the GPU. AMD’s encoding engine doesn’t affect the sport’s framerate practically as a lot, nevertheless it drops about 90% of the frames when the GPU is being closely used, making it ineffective as we already mentioned earlier.

Game Streaming Investigation: Which Quality Settings Are Best?

Game Streaming Investigation: Which Quality Settings Are Best?

Software encoding efficiency depends upon the kind of sport you’re taking part in. In the case of Assassin’s Creed Odyssey which closely makes use of each the CPU and GPU, streaming utilizing the CPU could have a noticeable have an effect on on body fee, and top quality encoding presets will wrestle to maintain up.

With the Core i7-8700Ok and the RTX 2080 taking part in Odyssey utilizing our customized high quality preset, we had been solely in a position to encode the sport utilizing the x264 veryfast preset with out affected by body drops within the stream output. X264 veryfast encoding additionally decreased the body fee by 17%, which was a bigger discount than merely utilizing NVENC. Veryfast encoding is best visually than NVENC for this kind of sport, so the efficiency hit is price it.

However shifting to even the ‘faster’ preset introduces body drops into the stream output. With a body drop fee of 8.5%, the output is stuttery and arduous to observe. Meanwhile, sport efficiency has dropped from 90 FPS on common, to simply 63 FPS with a 1% low solely simply above 30 FPS. It’s clear this preset is choking the system. And it will get worse with quick and medium, which see body drop charges of 62 and 82 p.c respectively. Interestingly, sport efficiency is barely higher with these presets than with quicker, however I think that’s because of the encoder being overwhelmed which permits the sport to get a small quantity extra CPU headroom for rendering the sport.

One technique to enhance efficiency may be to cap the sport to 60 FPS, as these watching your stream will probably be restricted to 60 FPS anyway. But with this cover in place, the story isn’t significantly better: the quick preset nonetheless sees 9% of all frames dropped, whereas the quicker preset simply scrapes in with no body drops, however with a 1% low within the sport of round 40 FPS. The solely choice to make use of quick could be to scale back the visible high quality and check out once more, however for this text we weren’t actually excited by optimizing Assassin’s Creed particularly for streaming with our {hardware}.

With the 8700Ok restricted to veryfast streaming or GPU streaming on this title, it is going to be fascinating to see how different CPUs stack up partially 2 of this investigation. But definitely with the 8700Ok – a high-end, common gaming CPU – what we’ve proven here’s a typical situation for streaming in a title that closely makes use of the CPU and GPU. Those with lower-tier CPUs and particularly, decrease core depend Intel CPUs, will run into this veryfast restrict extra typically.

Game Streaming Investigation: Which Quality Settings Are Best?

Game Streaming Investigation: Which Quality Settings Are Best?

As for Forza Horizon 4, which is much much less demanding on the CPU, it’s an fascinating scenario as a result of software program encoding on the CPU truly delivers greater sport efficiency than {hardware} accelerated GPU encoding. This is as a result of there’s loads of CPU headroom to encode on the CPU with out consuming in to GPU efficiency.

Using the x264 veryfast preset impacted sport efficiency by 6% 1% lows, however the distinction between veryfast and quick was solely an additional 5% drop regardless of the large improve in CPU energy required to encode utilizing the quick preset.

On the stream aspect, we noticed no body drops with the veryfast and quicker presets, nonetheless shifting to quick noticed a 12% body drop fee for the encoded stream. This prompted disagreeable stuttering within the stream. However contemplating we’re working the sport at practically 120 FPS, we are able to fairly simply implement a 60 FPS cap to scale back the sport’s stress on the CPU. With that cap in place, the quick preset turns into usable with zero body drops within the output. The cap additionally opens up the choice of medium preset encoding, though with the 8700Ok we nonetheless noticed round a 2% of all frames dropped with the 60 FPS cap in place, which isn’t splendid. If we wished to go along with medium encoding we’d have to have a look at lowering the sport’s CPU load by means of high quality setting tweaks.

Wrap Up (Until Part 2 of this Series)

So with all that testing achieved, there’s just a few fascinating takeaways right here. The key discovering for GPU patrons for the time being is that Turing’s GPU encoding engine for H.264 isn’t considerably improved in comparison with Pascal and definitely doesn’t flip GPU encoding right into a viable choice for streaming.

The solely time I’d recommend utilizing NVENC is with quick paced, excessive movement video games with a system that can’t CPU encode utilizing the x264 quicker preset or higher. Games with much less movement must be encoded utilizing the veryfast x264 preset moderately than NVENC, and veryfast must be achievable on most PCs which have been constructed with streaming in thoughts.

On the AMD entrance, their encoding engine wants loads of work to be even thought-about. It doesn’t work with excessive GPU masses and when it does work, the output high quality is horrible.

Game Streaming Investigation: Which Quality Settings Are Best?

CPU encoding is clearly a extra difficult story as what degree of x264 encoding you possibly can handle will rely in your CPU and, crucially, the kind of sport you might be taking part in. With our 8700Ok system we ranged from being caught with veryfast encoding in a CPU demanding sport, to having the ability to use the quick and even medium preset with a gentle 60 FPS sport output at respectable high quality settings in a much less CPU demanding title.

But what streamers must be aiming for is to make use of the quick preset at a minimal, that’s the primary preset the place the output high quality is respectable sufficient at 6 Mbps for Twitch streaming, and whereas it’s not incredible for quick movement scenes, quick is significantly better than both the quicker or veryfast presets but it’s nonetheless achievable on respectable {hardware}. Medium can be price making an attempt for these with top-end methods, whereas I actually wouldn’t trouble with any of the even slower presets.

While it’s good to have the ability to sport and stream on the one PC, this recommendation actually solely applies to informal or part-time streamers. Anyone who’s streaming professionally or full time ought to use a second, devoted stream seize PC with a good seize card and CPU. This then totally offloads the encoding work, permitting you to comfortably use the medium preset or slower for the very best quality streams, with out impacting your sport efficiency.

We’ve now found what the optimum presets are from a top quality perspective. The second a part of this collection on sport streaming we’ll examine which CPUs are able to encoding at these presets, so keep tuned for that.

Shopping Shortcuts

Masthead credit score: Sean Do