Nvidia RTX 3080 Gaming Performance at 1440p: CPU or Architecture Bottleneck?

It's time we become to explore something we've been eager to investigate since our 24-hour interval-i GeForce RTX 3080 review, and that's the weaker-than-expected resolution scaling of the new Ampere compages.

At present before nosotros get into it, practice note, this article is not designed to change your stance (our ours) well-nigh Ampere. The RTX 3080 is the best value high-end GPU on the market place by a state mile... if you can become your easily on one. But dorsum to Ampere and its interesting quirks, the aim hither is to investigate and explicate what'southward going on.

For those of yous not up to speed, in our RTX 3080 review nosotros institute that gaming performance at 1440p was non every bit impressive relative to what was seen at 4K. We saw this as did many other reviewers, some of which simply suggested it was a CPU bottleneck, the RTX 3080 is powerful enough that even the latest and greatest CPUs can't keep up.

But simply writing this off equally a CPU outcome didn't sit down correct with us. In our review nosotros tested with both the Ryzen 9 3950X and Core i9-10900K and both often saw the same resolution scaling. We noted role of the reason for the weaker than expected 1440p performance was downwardly to the Ampere compages and the modify to the SM configuration. The two times FP32 blueprint can only be fully utilized at 4K and beyond. This is considering at 4K the portion of the return fourth dimension per frame is heavier on FP32 shaders. At lower resolutions like 1440p, the vertice and triangle load is identical to what we see at 4K, but at the higher resolution pixel shaders and compute effect shaders are more intensive, so take longer and therefore can fill the SMs FP32 ALUs better.

We oftentimes see high performance GPUs meliorate utilized at higher resolutions for similar reasons, and then that in itself isn't unusual. Higher resolutions always tend to put core-heavy GPUs to piece of work improve, but they also minimize other organisation's bottlenecks.

In our RTX 3080 review, we could also come across how the RTX 2080 Ti extended its pb over the vanilla 2080 at 4K, going from ~23% faster at 1440p to ~28% faster at 4K. That's only a five% operation disparity and the scaling at 1440p and 4K looks very like.

With the RTX 3080 nosotros saw a 21% advantage over the 2080 Ti at 1440p and so a much larger 32% margin at 4K. Nosotros suggested this could be explained by the Ampere architecture's nature which is more than compute heavy, datacenter and AI oriented than gaming-kickoff. So with this article we're going to explore how true that statement is past calculation 1080p and 720p data to the 14 games we test with. If we're seeing CPU performance influence the 1440p results, this will become very apparent with the 1080p data and extremely obvious at 720p.

For this test we'll be running a Core i9-10900K at stock clocks and comparing the RTX 3080 against the 2080 Ti. Turing isn't necessarily the best architecture at efficiently scaling lower resolutions, just it does seem to exist ameliorate than Ampere and considering there's no other GPU that comes close in terms of performance, it is what has to be used. Let's get into the results.

Benchmarks

Starting with Death Stranding nosotros meet that frame rates for the 2080 Ti increased past 68% when moving from 4K to 1440p, and and then 28% from 1440p to 1080p before maxing out at 201 fps at 720p. The RTX 3080 saw a 53% operation increase when dropping downward to 1440p from 4K, and and then simply a further eleven% increase from 1440p to 1080p.

By the time we hitting the 1080p resolution we start to see the CPU limit functioning, leaving very trivial headroom at 720p. That'due south interesting to note and it does mean that in that location's no CPU limitation at 1440p, and then the weaker scaling cannot be blamed on the 10900K, not i bit.

Microsoft Flight Simulator 2022 is heavily limited by CPU performance every bit its DX11 implementation by and large hammers a unmarried cadre. Based on what we're seeing here information technology's plausible that the RTX 3080 is limited with the 10900K at 1440p, though given we do come across a niggling more functioning at 1080p and then a hard limit at 720p, nosotros'd say we're simply shy of limiting the 3080 at 1440p in this championship.

Now if you idea the RTX 3080 was in any way CPU limited in Shadow of the Tomb Raider, well you'd be wrong. Starting with the 2080 Ti results, we're seeing an 82% performance uplift when dropping the resolution from 4K to 1440p, then a 45% increment from 1440p to 1080p and a further 47% increment from 1080p to 720p.

The RTX 3080 appears to scale reasonably well equally functioning is improved by 76% when dropping downwardly to 1440p from 4K, and so a 42% increase from 1440p to 1080p and finally a 33% increase from 1080p to 720p at which point the CPU might be starting to become the bottleneck. In other words, we're seeing good scaling from the 3080 in this game.

Next up nosotros take the Rainbow Half-dozen Siege where nosotros're conspicuously non CPU limited at 1080p, permit lonely 1440p. As nosotros often see in Vulkan-based titles, scaling for cadre-heavy GPUs is actually quite skillful here.

Relative to the 2080 Ti, the RTX 3080 scales quite well, whereas the 2080 Ti sees a 98% improvement when lowering the resolution to 1440p, the RTX 3080 saw a ninety% comeback.

F1 2022 is some other game where we're not CPU express fifty-fifty at 1080p with the RTX 3080/10900K combo. Resolution scaling is likewise much amend with the RTX 2080 Ti, which saw a 66% functioning uplift when reducing the resolution from 4K to 1440p and and then xxx% from 1440p to 1080p. The RTX 3080 merely saw a 56% functioning improvement when lowering the resolution from 4K to 1440p and and then 27% from 1440p to 1080p.

Nosotros also find no CPU bottleneck in Gears v with the RTX 3080, all the way down to 1080p. The 2080 Ti does scale better from 4K to 1440p, but it's not a significant difference. The margin does widen when going from 1440p to 1080p, but we are starting to approach the hard limits of the CPU.

The RTX 2080 Ti scales considerably amend in Horizon Zero Dawn. We see that from 4K to 1440p the Turing GPU enjoys an 83% operation heave, and then a 46% boost from 1440p to 1080p. The RTX 3080 sees a 70% performance increase when lowering the resolution from 4K to 1440p, and then just 21% from 1440p to 1080p despite not running into a CPU bottleneck. The game simply can't continue with all those CUDA cores loaded with piece of work at these lower resolutions and therefore efficiency drops off considerably.

It'south a similar story when testing with Assassin's Creed Odyssey. The 2080 Ti saw a 49% spring when lowering the resolution to 1440p, while the 3080 gets bumped by just 34%, and a similar matter is seen when reducing the resolution from 1440p to 1080p.

World War Z is another title based on the Vulkan API which sees skilful utilization for the RTX 3080, fifty-fifty at 1440p. In this example nosotros exercise run into a CPU bottleneck, evidenced by the 1% low results. These results are non an case of the Ampere architecture scaling poorly across lower resolutions, only rather an example of a game that does become CPU limited at 1440p even with a fast Core i9 CPU when coupled with a loftier performance GPU.

Metro Exodus is a bit strange when it comes to functioning, though we are talking about frame rates up effectually 200 fps. At that place's some kind of bottleneck going on with the RTX 3080, only nosotros don't recollect it'southward necessarily the CPU, only rather a driver overhead effect that affects scheduling for core heavy GPUs like the RTX 3080.

Either style, we recollect these results are very interesting. The 2080 Ti and 3080 deliver identical performance at 1080p, while the 2080 Ti gains more performance when lowering the resolution to 720p. Of grade, this 720p performance metric is irrelevant for gaming as no 1 is going to employ it, but it does show how Turing appears to scale meliorate at lower resolutions.

Resolution scaling operation is fairly consequent in Resident Evil 3 between the 2080 Ti and 3080. Both saw roughly a 90% functioning uplift when dropping from 4K to 144p, and then exactly 47% when going from 1440p to 1080p. It'south not until we drop down to 720p that the 2080 Ti sees a larger performance gain, just we could also be reaching the limits of the CPU with the RTX 3080 which in absolute terms remains the faster GPU at all resolutions regardless.

Moving on to Doom Eternal, this is a game you might take expected to scale well on the RTX 3080, at least I did. While non terrible, we're getting much better margins with the 2080 Ti which saw an fourscore% performance increase when going from 4K to 1440p, the 3080 on the other paw saw a 66% comeback. In that location is no chance the CPU is limiting performance at 1440p given we see almost 50% more frames when dropping right down to 720p.

Despite what we saw in Doom Eternal, scaling between the 2080 Ti and 3080 is very consistent in Wolfenstein: Youngblood. Both saw a 75% operation boost when dropping the resolution from 4K to 1440p and frankly this is more what we expected to see in Doom.

Finally we take Hitman ii which does start to limit the operation of the RTX 3080 at 1440p due to the CPU, though we think this is downward to how the game is coded.

Here'south a wait at the fourteen game average which lines upwardly exactly with what we saw in our GeForce RTX 3080 review using the Ryzen 9 3950X. The 2080 Ti scales ~10% better from 4K to 1440p on average, with a similar margin seen when going from 1440p to 1080p.

What Nosotros Learned

Based on the results nosotros just saw, going into lower resolutions and not scaling performance as previous architectures, we can't always blame Ampere for this, while equally we can't ever arraign a CPU bottleneck. It volition depend on the game and the hardware used for testing.

It's clear though that in games like Assassin'south Creed Odyssey, Doom Eternal, F1 2022, Horizon Zero Dawn and Rainbow Six Siege, the Ampere compages is what limits 1440p performance relative to what's seen at 4K. In those games there was no CPU bottleneck at the 1440p resolution, and the aforementioned was true for fifty-fifty 1080p. Decease Stranding is another game that didn't encounter a CPU bottleneck at 1440p, just we did outset to detect the CPU limitations at 1080p. A similar situation was seen with Gears 5 and then some weirdness in Metro Exodus that was likely the result of a combination of things.

Then we found merely three examples where you could arraign the CPU for limiting 1440p performance, or at least information technology was correct on the verge of doing so: Hitman 2, Microsoft Flight Simulator 2022 and Globe War Z.

We also saw 3 examples where the Ampere architecture scaled very well, at least relative to the 2080 Ti: Resident Evil 3, Shadow of the Tomb Raider, and Wolfenstein Youngblood. And so it'south not ever that 1440p functioning is limited relative to the 4K throughput, and this was seen in our mean solar day-one review where the RTX 3080 ranged anywhere from ~70% faster than the vanilla RTX 2080 to equally little equally forty% when not CPU limited.

Our overall outlook for the RTX 3080 has not inverse, and that ways the GPU is on average well-nigh seventy% faster than the 2080 at 4K, and 50% faster at 1440p which is awesome.

It'll be interesting to see if AMD can deliver a gaming-focused GPU with RTX 3080/3090-like functioning at 4K and if so, if they can evangelize a performance advantage at lower resolutions like 1440p where Ampere is oft less impressive.

Claiming the RTX 3080 is CPU express at 1440p, assuming you're using Core i7-8700K or better, chances are more oft than non you'll be incorrect on that phone call. Merely this really wasn't about right or wrong, but rather working out what's going on as that helps you work out what yous do or don't need to upgrade.

On that note, we'll accept a follow upward benchmark exam with the RTX 3080 using the $200 Ryzen five 3600, both running at stock and overclocked with manually tuned retentiveness, and then we'll have those results and pit them against the 3950X and 10900K. Stay tuned for that comparing before long.