Does the i5-11400 Bottleneck the RTX 3070? Let‘s Break Down the Benchmarks

As an avid gamer and PC builder, one of the most common questions I‘m asked when recommending high-end graphic card upgrades is: "Will my CPU be a bottleneck?"

And for good reason – you want to make sure your shiny new GPU can stretch its legs and isn‘t held back by an older processor. Especially with GPU shortages, some gamers are running newer cards like the RTX 3070 with older CPUs.

So today we‘ll be diving deep on the performance of the popular i5-11400 paired with the RTX 3070 Founders Edition to see if there is any noticeable bottlenecking at various resolutions and game settings.

TLDR: At 1440p or 4K resolutions, there is no discernible bottleneck. At 1080p with ultra settings, a minor bottleneck of around ~10-15% can occur in some games, but performance is still excellent.

Quick Bottleneck Definition

For those newer to PC building, a bottleneck occurs when one component, like the CPU, limits the performance of another component like the graphics card. This is commonly seen when pairing a very fast, high-end GPU with an underpowered CPU. The GPU can‘t reach full utilization since the CPU can‘t keep up with preparing enough draw calls and frames.

Symptoms of bottlenecking can include lower than expected performance, stuttering, dropped frames, etc. Typically it is most visible at 1080p resolution, where the CPU workload is highest. At higher resolutions, the GPU demands increase and shift to being the limiting factor instead.

Now let‘s see how the 6 core/12 thread i5-11400 pairs up with the powerhouse RTX 3070…

RTX 3070 Overview

Quick refresher – the RTX 3070 brings excellent 1440p gaming performance near that of last generation‘s 2080 Ti flagship, at less than half the current market price. With modern features like DLSS, ray tracing, and NVENC encoding support there is a lot to love.

For testing, I‘ll be looking specifically at the Nvidia Founders Edition model which has stock boost clocks of 1725 MHz. Aftermarket models perform similarly but can sustain slightly higher clocks when thermals permit.

i5-11400 Overview

The i5-11400 brings major single threaded gains over previous generation parts, with Cypress Cove performance that rivals the older i9-10900K. And while multicore throughput is admittedly more average, with gaming workloads tending to favor stronger single thread perf, the i5 makes an interesting pairing.

Especially considering the meteoric rise in 6 core/12 thread CPU pricing, landing at an MSRP of $200 makes this hyperthreaded 6 core part an intriguing budget to mid-range choice. That is IF it can keep pace with faster graphic cards…

• 6 Cores / 12 Threads
• Up to 4.4Ghz Turbo Boost
• Cypress Cove 14nm
• 65W TDP

Now let‘s investigate some benchmarks and see how well matched this CPU/GPU combo performs in the real-world!

Bottleneck Testing Methodology

To accurately quantify any bottlenecking percentage between the CPU and GPU, we need to compare the 11400 and 3070 combo against standalone data from these components.

Ideally we would use isolated benchmarks from these exact components at different resolutions with the same accompanying hardware. Comparing performance when paired together versus standlone metrics gives the bottlenecking delta if present.

Lacking standalone benchmark data, I instead compiled benchmark figures from reviews featuring nearly identical test bench setups. The only variable differing is the main component being swapped – either the CPU or GPU.

This allows us to calculate total system performance changes in various games at the same settings to quantify any potential slowdowns from bottlenecks.

1080p Ultra Settings Performance

First let‘s investigate the highest CPU load scenario – maximum game settings paired with the lowest resolution. Higher framerates also shift more load towards the CPU instead of GPU, so this is a classic potential trouble spot:

Benchmark sources:

• TechSpot: 12 Game Benchmark, RTX 3070 & i5-11400
• Tom‘s Hardware: RTX 3070 Standalone

So what do these figures tell us? When really pushing the limits at 1080p, we do see a minor CPU bottleneck of around ~8.5%, or 10-15 fps slower than the 3070‘s full potential. This delta will vary further depending on the game engine and settings used.

However, despite the mathematical bottleneck the delivered gaming experience is still superb – reliably over 100 fps at max settings is incredible. That extra 15 fps headroom on the GPU simply wouldn‘t be realized except by competitive esports gamers with 240 hz displays.

So in the context of actual gameplay, while present this bottleneck should not majorly influence real-world results. Unless you fall into that highly competitive category chasing every last frame, rest assured performance will impress.

1440p & 4K Resolution Testing

Now let‘s examine higher resolutions that shift to being more GPU limited and alleviate any CPU bottlenecks:

Here we see the bottleneck shrink to only a few percentage points, an almost negligible difference. At higher resolutions, potential CPU limitations fade out of view and the monumental rendering workload shifts squarely onto the GPU.

Ultrawide or 4K testing would show an even smaller CPU influence. Once resolutions exceed 1440p, even lower tier modern CPUs can rarely hinder performance for top of the line GPUs.

When Does Bottlenecking Normally Occur?

As a general guideline:

• Bottlenecking is most likely with 1080p resolution
• Runs risk with framerates over 120-144 fps
• Typical in esports/competitive games
• CPU-intensive games see large bottlenecking (AC: Valhalla, strategy, simulation titles)
• Worsens with background CPU load like streams/video

If none of those scenarios apply to you, performance differences should be minimal even with a moderate CPU and beastly GPU.

RTX 3070 & i5-11400 Feasibility Overview

• Excellent 1440p matching with high frame rates on ultra
• Won‘t limit max settings 4K 60 fps gaming
• Provides good future headroom as GPU demands rise
• Occasional minor limiting at 1080p peak conditions
• Great bang for buck performance combination

For the majority of gamers, especially at 1440p or 4K resolutions, I don‘t believe the i5-11400 meaningfully bottlenecks the RTX 3070 or restricts delivering incredible gaming experiences.

Only elite esports players pursuing 360+ fps or enthusiasts seeking bragging rights in synthetic benchmarks are likely to feel constrained. For literally every other gamer and use case, this combo achieves fantastic results!

Upgrade Considerations

• If gaming at 1080p with a 240hz+ monitor, consider upgrading to an i7-12700K or faster CPU
• When streaming + gaming simultaneously, a 8 core / 16 thread CPU removes streaming impact
• Overclocking headroom greatly improved with a K-SKU Intel chip (12600K), or Ryzen alternative

Otherwise enjoy the awesome value and performance the i5-11400 and RTX 3070 offer! When shopping for a new GPU, power supply, case, and other supporting parts, check out my RTX 3070 & i5-11400 build guide here for component recommendations.

Let me know if you have any other questions!