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

It'south time nosotros get to explore something we've been eager to investigate since our day-i GeForce RTX 3080 review, and that'southward the weaker-than-expected resolution scaling of the new Ampere architecture.

Now before we get into it, do note, this article is not designed to alter your stance (our ours) most Ampere. The RTX 3080 is the best value high-end GPU on the market by a state mile... if you tin become your hands on one. Simply dorsum to Ampere and its interesting quirks, the aim hither is to investigate and explain what'south going on.

For those of you not up to speed, in our RTX 3080 review we institute that gaming performance at 1440p was not as impressive relative to what was seen at 4K. Nosotros saw this every bit did many other reviewers, some of which simply suggested it was a CPU bottleneck, the RTX 3080 is powerful plenty that even the latest and greatest CPUs tin't continue upwards.

But but writing this off equally a CPU effect didn't sit down right with united states of america. In our review we tested with both the Ryzen ix 3950X and Core i9-10900K and both frequently saw the same resolution scaling. We noted function of the reason for the weaker than expected 1440p performance was down to the Ampere architecture and the alter to the SM configuration. The two times FP32 blueprint can only be fully utilized at 4K and beyond. This is because at 4K the portion of the render fourth dimension per frame is heavier on FP32 shaders. At lower resolutions like 1440p, the vertice and triangle load is identical to what nosotros run across at 4K, but at the higher resolution pixel shaders and compute effect shaders are more intensive, so accept longer and therefore tin fill the SMs FP32 ALUs meliorate.

We often run into loftier operation GPUs better utilized at higher resolutions for similar reasons, and so that in itself isn't unusual. College resolutions always tend to put cadre-heavy GPUs to work better, just they also minimize other organization's bottlenecks.

In our RTX 3080 review, we could also see how the RTX 2080 Ti extended its lead over the vanilla 2080 at 4K, going from ~23% faster at 1440p to ~28% faster at 4K. That's merely a 5% performance disparity and the scaling at 1440p and 4K looks very similar.

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

For this examination we'll exist running a Core i9-10900K at stock clocks and comparing the RTX 3080 confronting the 2080 Ti. Turing isn't necessarily the all-time architecture at efficiently scaling lower resolutions, but information technology does seem to be ameliorate than Ampere and considering at that place's no other GPU that comes shut in terms of performance, it is what has to exist used. Let's go into the results.

Benchmarks

Starting with Death Stranding nosotros see that frame rates for the 2080 Ti increased past 68% when moving from 4K to 1440p, and and so 28% from 1440p to 1080p before maxing out at 201 fps at 720p. The RTX 3080 saw a 53% performance increment when dropping downwardly to 1440p from 4K, and so only a further 11% increase from 1440p to 1080p.

By the time we hit the 1080p resolution nosotros start to come across the CPU limit operation, leaving very little headroom at 720p. That'south interesting to note and information technology does mean that there's no CPU limitation at 1440p, and then the weaker scaling cannot be blamed on the 10900K, not one bit.

Microsoft Flight Simulator 2022 is heavily limited by CPU performance as its DX11 implementation mostly hammers a single core. Based on what we're seeing hither information technology'southward plausible that the RTX 3080 is limited with the 10900K at 1440p, though given we do meet a little more than functioning at 1080p and then a difficult limit at 720p, nosotros'd say we're simply shy of limiting the 3080 at 1440p in this title.

Now if you thought 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, nosotros're seeing an 82% operation uplift when dropping the resolution from 4K to 1440p, then a 45% increase from 1440p to 1080p and a farther 47% increase from 1080p to 720p.

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

Side by side up nosotros take the Rainbow Six Siege where we're clearly not CPU express at 1080p, let alone 1440p. As we frequently run across in Vulkan-based titles, scaling for core-heavy GPUs is really quite adept 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 90% comeback.

F1 2022 is another game where we're non CPU express even at 1080p with the RTX 3080/10900K combo. Resolution scaling is besides much better with the RTX 2080 Ti, which saw a 66% operation uplift when reducing the resolution from 4K to 1440p and then thirty% from 1440p to 1080p. The RTX 3080 only saw a 56% performance improvement when lowering the resolution from 4K to 1440p and then 27% from 1440p to 1080p.

We also find no CPU bottleneck in Gears five with the RTX 3080, all the way downwardly to 1080p. The 2080 Ti does scale ameliorate from 4K to 1440p, but it's not a significant departure. The margin does widen when going from 1440p to 1080p, but we are starting to arroyo the hard limits of the CPU.

The RTX 2080 Ti scales considerably meliorate in Horizon Nada Dawn. We see that from 4K to 1440p the Turing GPU enjoys an 83% performance boost, 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 and so simply 21% from 1440p to 1080p despite non running into a CPU clogging. The game merely can't keep with all those CUDA cores loaded with work at these lower resolutions and therefore efficiency drops off considerably.

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

Globe State of war Z is another championship based on the Vulkan API which sees good utilization for the RTX 3080, even at 1440p. In this instance nosotros do come across a CPU bottleneck, evidenced by the one% low results. These results are non an case of the Ampere compages scaling poorly across lower resolutions, but rather an example of a game that does become CPU limited at 1440p even with a fast Core i9 CPU when coupled with a high operation GPU.

Metro Exodus is a bit strange when information technology comes to operation, though nosotros are talking about frame rates up around 200 fps. In that location's some kind of clogging going on with the RTX 3080, merely we don't think it'due south necessarily the CPU, but rather a driver overhead consequence that affects scheduling for core heavy GPUs like the RTX 3080.

Either way, nosotros think 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 course, this 720p performance metric is irrelevant for gaming as no i is going to use it, but information technology does show how Turing appears to scale better at lower resolutions.

Resolution scaling performance is fairly consistent in Resident Evil 3 between the 2080 Ti and 3080. Both saw roughly a 90% performance uplift when dropping from 4K to 144p, and and then exactly 47% when going from 1440p to 1080p. It's not until we driblet downwards to 720p that the 2080 Ti sees a larger performance gain, just nosotros could also exist 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 yous might have expected to scale well on the RTX 3080, at least I did. While not terrible, nosotros're getting much better margins with the 2080 Ti which saw an 80% functioning increase when going from 4K to 1440p, the 3080 on the other hand saw a 66% improvement. There is no chance the CPU is limiting performance at 1440p given nosotros run across almost 50% more than 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% performance boost when dropping the resolution from 4K to 1440p and bluntly this is more what we expected to run across in Doom.

Finally nosotros take Hitman two which does commencement to limit the performance of the RTX 3080 at 1440p due to the CPU, though nosotros remember this is down to how the game is coded.

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

What We Learned

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

It's articulate though that in games similar Assassin'southward Creed Odyssey, Doom Eternal, F1 2022, Horizon Zero Dawn and Rainbow Six Siege, the Ampere architecture is what limits 1440p performance relative to what'due south seen at 4K. In those games there was no CPU bottleneck at the 1440p resolution, and the same was true for even 1080p. Death Stranding is another game that didn't run into a CPU clogging at 1440p, but we did commencement to find the CPU limitations at 1080p. A similar situation was seen with Gears 5 then some weirdness in Metro Exodus that was likely the result of a combination of things.

Then nosotros plant just three examples where you could blame the CPU for limiting 1440p performance, or at to the lowest degree information technology was right on the verge of doing and so: Hitman two, Microsoft Flight Simulator 2022 and World War Z.

We also saw three examples where the Ampere compages scaled very well, at least relative to the 2080 Ti: Resident Evil 3, Shadow of the Tomb Raider, and Wolfenstein Youngblood. So it'south not always that 1440p performance is limited relative to the 4K throughput, and this was seen in our day-i review where the RTX 3080 ranged anywhere from ~70% faster than the vanilla RTX 2080 to as piffling as 40% when not CPU limited.

Our overall outlook for the RTX 3080 has not changed, and that means the GPU is on average about 70% faster than the 2080 at 4K, and 50% faster at 1440p which is awesome.

It'll exist interesting to run into if AMD can deliver a gaming-focused GPU with RTX 3080/3090-like operation at 4K and if then, if they can deliver a functioning reward at lower resolutions like 1440p where Ampere is often less impressive.

Claiming the RTX 3080 is CPU limited at 1440p, assuming you're using Core i7-8700K or better, chances are more often than not y'all'll be incorrect on that telephone call. Merely this really wasn't well-nigh correct or wrong, but rather working out what's going on as that helps you piece of work out what y'all do or don't need to upgrade.

On that notation, we'll accept a follow upwards benchmark test with the RTX 3080 using the $200 Ryzen 5 3600, both running at stock and overclocked with manually tuned memory, and then nosotros'll take those results and pit them against the 3950X and 10900K. Stay tuned for that comparison soon.