RTX 4090 vs 6900 XT: Which GPU is Best?

RTX 4090 vs 6900 XT

While NVIDIA’s GeForce RTX 4090 and AMD’s Radeon RX 6900 XT offer completely different levels of performance, they’re both definitively high-end GPUs. Their performance difference speaks more to great next-gen capabilities than to previous-gen weaknesses.

As such, comparing the 4090 vs 6900 XT is important if you’re deciding on a high-end graphics card. This is especially true given the big price difference between the two cards.

If you want the absolute best graphics card money can buy, then the RTX 4090 is the clear winner. But if you care about price-performance and feature offerings, there’s more to the story.

To figure out which GPU is best ‘all things considered’, we need to compare their two price-performance offerings and their brand-specific features. We must also consider what the GPU market holds in store for us over the coming months, because there are other competing graphics cards on the horizon.

Buying Options

RTX 4090 Advantages

  • Almost 100% faster at 4K
  • Almost 50% faster at 1440p
  • Much better ray tracing performance
  • DLSS 3.0 is a game-changer for ‘free’ performance
  • Better memory configuration for longevity

RX 6900 XT Advantages

  • Currently $1,500 (68%) cheaper
  • Capable of 4K gaming at 100fps
  • Requires 150W less power
  • Can game at high refresh rates at any resolution

What is the NVIDIA GeForce RTX 4090?

The NVIDIA GeForce RTX 4090 launched in October 2022 as the first of NVIDIA’s 40-series graphics cards and is currently the most powerful consumer GPU on the market.

Based on NVIDIA’s ‘Ada Lovelace’ architecture, it’s manufactured using TSMC’s 4N process. It boasts the latest graphics tech capabilities like cutting-edge image upscaling techniques, and it delivers flagship rasterization performance.

What is the AMD Radeon RX 6900 XT?

The AMD Radeon RX 6900 XT is a high-end graphics card that launched in December 2020. It competed with NVIDIA’s previous-gen RTX 3080 and RTX 3090, and still competes with the current-gen 40-series GPUs thanks to its lower price.

The 6900 XT is based on AMD’s ‘RDNA 2’ architecture and is manufactured using TSMC’s 7nm process. It doesn’t boast every feature that the latest NVIDIA GPUs offer, but it boasts great rasterization performance across all resolutions and is a great high-end price-performance offering.

NVIDIA vs AMD Features

Because they’re made by two different companies, the RTX 4090 and RX 6900 XT have different—but similar—feature offerings.

In general, NVIDIA GPUs can do all that AMD GPUs can, but can often do a little more, or the same but a little differently.

DLSS and FSR

One feature of NVIDIA graphics cards that’s most important to gamers is Deep Learning Super Sampling (DLSS). This tech allows the GPU to upscale low-resolution images into high resolution ones using AI or Deep Learning. AMD cards can’t use DLSS, but they do offer an alternative feature called ‘FidelityFX Super Resolution’ (FSR).

Both DLSS and FSR increase performance by reducing the number of pixels rendered by the GPU every frame and then increasing the number again using Deep Learning rather than raw GPU horsepower. This helps maintain your game’s graphical quality while improving performance.

DLSS tends to look slightly better than FSR. AMD cards can only use FSR, but NVIDIA cards can use both technologies. NVIDIA 40-series GPUs like the RTX 4090 can also use DLSS 3.0, which uses AI to generate frames between GPU-rendered ones, greatly increasing performance over and above even previous generations of DLSS.

GSync and FreeSync

Most modern monitors come with one of three different display technologies: GSync, GSync Compatible, and FreeSync. When paired with compatible video cards, these displays synchronize their refresh rates with your game’s framerate to avoid screen tearing.

Read More: G-Sync vs FreeSync: Which Adaptive Sync Tech is Better?

However, just like with DLSS/FSR, Nvidia GPUs have an edge here, because they support both GSync and FreeSync, whereas AMD GPUs only support the latter.

NVIDIA Reflex, NULL, and AMD Anti-Lag

Both NVIDIA and AMD offer drivers that provide input lag reduction features, which help reduce the time between when you press a button and when your character performs an action on-screen. These features are NVIDIA’s ‘NULL’ and AMD’s ‘Anti-Lag’.

Also Read: What is Input Lag & How Can You Fix/Test It?

However, if the game supports it, NVIDIA also offers an alternative called Reflex. Reflex aims to reduce input latency by making your hardware process everything just before a frame is needed to display on screen.

AMD Anti-Lag works with DirectX 12, so it’s supported in most modern games. NULL, on the other hand, isn’t supported by DX12.

DLDSR and VSR

NVIDIA DLDSR and AMD VSR technology makes your graphics card render your game at a higher resolution than your native resolution and downsamples this image back to your display’s native resolution for improved clarity.

Both technologies work pretty well, and each has its pros and cons. Neither DLDSR nor VSR tech is widely used among gamers, so these features won’t be of much concern for most people.

4090 vs 6900 XT: Price Comparison

The RTX 4090 has an MSRP of $1,599, and the RX 6900 XT has an MSRP of $999.

The RTX 4090 retails well above its MSRP in practice. It can currently be found going for between $2,200-$2,700 online. The RX 6900 XT, however, can be found going for between $700-$1,300 online.

This means that, in real prices today, you’ll probably be able to pick up a 6900 XT for $1,500—or 68%—cheaper than some of the cheapest RTX 4090s.

Alternative GPUs

The RTX 4090 doesn’t have a similarly high-end competitor card at the moment. However, new AMD cards are just around the corner, and they might compete with the 4090. The RTX 4080 gets close, but not close enough given its big price tag.

Also Read: RTX 4080 vs 4090: Is NVIDIA’s Fastest GPU Worth the Extra Cost?

If you’re happy with performance similar to what the RX 6900 XT offers, however, you could try opting for an RTX 3090 or RTX 3080, which both perform about the same as the 6900 XT—although the 3090 beats the 6900 XT by a fair margin at higher resolutions.

Graphics Card Specs

RTX 4090 RX 6900 XT
GPU AD102 Navi 21
CUDA Cores / Stream Processors 16,384 5,120
Tensor Cores 512
RT Cores / Ray Accelerators 128 80
Stream Multiprocessors / Compute Units 128 80
Memory 24GB GDDR6X 16GB GDDR6
Memory speed 21GT/s 16GT/s
Memory bandwidth 1,008GB/s 512GB/s
Clock speed (base/boost) 2.23GHz / 2.52GHz 1.83GHz / 2.25GHz
Power connector (reference) 1x 16-pin 2x 8-pin
TDP 450W 300W

Both the 4090 and 6900 XT have the raw specification chops to promise high-end gaming performance. But even just judging from the specs, we can expect a significant performance difference.

Most tellingly, the 6900 XT has many fewer shader cores (CUDA Cores or Stream Processors) than the RTX 4090. It also has a substantial number fewer CUs than the NVIDIA GPU’s whopping 128 SM count. And, crucially, this translates to the number of RT Cores or Ray Accelerators, which aids ray tracing performance.

AMD GPUs usually have fewer shader cores but higher clock speeds, but we see that the 6900 XT has a lower base clock and boost clock than the 4090. Nevertheless, that the 6900 XT’s boost clock almost matches the next-gen 4090’s boost clock is impressive.

We can see that the 4090 is leaps and bounds ahead of the 6900 XT on the memory front, too. The 4090’s 384-bit memory bus runs rings around the 6900 XT’s 256-bus, which contributes to the NVIDIA card’s bandwidth being practically double the 6900 XT’s bandwidth.

Dimensions

RX 6900 XT RTX 4090 (FE)
Length 267mm 304mm
Width 120mm 137mm
Slots 3 3

Both the 6900 XT and 4090 are big, and both will require three case slots of room to house them. But the RTX 4090 also requires more case room to work with. As always, ensure that your case can house GPUs of this size before deciding to purchase one.

Power Draw

As we would expect, the more powerful NVIDIA GPU has a higher power draw of 450W vs 300W—which isn’t to say that the 6900 XT is more power efficient, because that depends on the power draw-performance ratio.

Also Read: The Best Power Supplies for 2023

Perhaps strangely, AMD recommends the same minimum 850W power supply wattage for its 6900 XT as NVIDIA recommends for its more power-hungry 4090.

Gaming Performance

The RTX 4090 and RX 6900 XT are high-end cards that should be more than enough for most gamers playing at any resolution. But, as we’ll see when comparing these GPUs across 1080p, 1440p, and 4K resolutions, they operate on completely different performance levels.

Also Read: 1080p vs. 1440p vs. 4K: Which Resolution Is Best for Gaming?

We’ve compared benchmark results for both cards across all three resolutions, using reviews like those from TechRadar, TechSpot, and TomsHardware as our baseline. We’ve averaged out the different framerate comparisons to give you an idea of how these cards compare, in general, on most systems.

These results are only averages, however, and performance differences will vary from game to game.

RX 6900 XT vs RTX 4090 | Test in 7 Games

1080p Benchmarks

At 1080p resolution, both the 6900 XT and 4090 are more than enough for gaming, even at high refresh rates.

Also Read: Response Time vs Refresh Rate: What’s the Difference?

If you’re a competitive gamer, you’re likely concerned about games that aren’t too demanding to run, and these titles should run at framerates in the multiple hundreds on both GPUs at 1080p. If that describes you, then it might be better to save your money and opt for a 6900 XT, which should see you climbing the game ladder without spending an arm and a leg.

However, while games are often CPU bound at 1080p, there’s still a significant difference between how the two graphics cards perform at this resolution. Benchmarks show that, on average, the 4090 performs about 25% faster than the 6900 XT. This might mean the 4090 would hit the 240fps average framerate threshold for 240Hz monitors in some moderately demanding titles where the 6900 XT wouldn’t.

1440p Benchmarks

At 1440p resolution, both graphics cards should average over 100fps in the vast majority of games being played on max settings.

Also Read: Is 1440P Worth it for Gaming?

However, benchmarks show that the RTX 4090 performs, on average, about 45% faster than the RX 6900 XT at this resolution. This might be especially important to you if you want to play more demanding games on max settings at high refresh rates.

In more demanding games, the 6900 XT will struggle to hit 120fps or 144fps when playing at max settings at this resolution. The 4090, on the other hand, should surpass these thresholds in all but the most excruciatingly demanding of titles.

Of course, if you don’t want to play the most demanding titles around, the 6900 XT will be more than enough for even high refresh rate gaming at 1440p. Similarly, if you don’t mind dropping your settings from maximum to high, high refresh rates are within your grasp even for very demanding titles with the 6900 XT.

4K Benchmarks

At 4K resolution, the RTX 4090 performs much better than the 6900 XT.

Also Read: Is 4K Worth it for Gaming? Why Most Gamers Don’t Need a 4K Monitor

Gaming at 4K resolution (if not also at 1440p) is arguably when opting for a 4090 over a 6900 XT makes the most sense from a price-performance perspective. At 4K, benchmarks show that the 4090 performs about 94% better than the 6900 XT on average.

Both graphics cards should net over 60fps even in moderately demanding titles at 4K resolution, but in most cases the 4090 will provide almost double the 6900 XT’s framerate (again, though, remember that this is very game-dependent, and in some games the margins are much slimmer).

Opting for a 4090 over a 6900 XT for 4K gaming will make more demanding games playable at, say, 80fps, while the 6900 XT might get well below 60fps. Similarly, in slightly less demanding games, you’ll be able to get over 120fps or 144fps with a 4090 where a 6900 XT would struggle to reach 100fps.

For this reason, whether you’re gaming with a 60Hz monitor or 144Hz monitor, if you’re wanting to play at 4K res, the 4090 will give you a much better experience across a wide variety of titles.

Ray Tracing and Upscaling

Apart from its 4K capabilities, the one area where the 4090 is light-years ahead of the 6900 XT is in ray tracing and upscaling performance.

Before NVIDIA’s 40-series graphics cards, AMD GPUs have never ray traced as well as their NVIDIA competitors, and this has only been highlighted now the RTX 4090 is in the mix.

Turning ray tracing on drops the 6900 XT’s framerate by about 75%, whereas it often drops the 4090’s framerate by less than 50%. And given that the 4090 is already operating at higher frame rates, this means that a 4090 with ray tracing enabled often performs as well as a 6900 XT with ray tracing disabled.

And when we throw DLSS 3.0 into the mix, the 4090’s performance seems almost like magic. By enabling DLSS 3.0, the 4090 can double its frame rates. This completely offsets ray tracing’s performance hit in most cases, and if you don’t care about ray tracing, then it makes extremely demanding titles run smooth enough for high refresh rate gaming, even at 4K resolution.

Performance Summary

While both graphics cards perform fantastically across all resolutions, the 4090 clearly has a substantial edge, especially at 4K.

At 1080p, both GPUs are overkill unless you want to do ultra-high refresh rate gaming—in which case, opting for a 6900 XT rather than a 4090 makes sense, because it costs much less and should still be able to hit high enough framerates.

As we move up through the different resolutions, we see an exponential increase in the performance disparity between the 6900 XT and 4090: from 25% at 1080p to 45% at 1440p to almost 100% at 4K. This makes the 4090 much more worth its salt at 4K than at 1080p and makes the comparison a difficult price-performance conundrum at 1440p.

More Performance Comparisons

4090 vs 6900 XT Verdict: Which High-End GPU is Best?

In terms of performance, both GPUs perform very well at any resolution. But while both the NVIDIA RTX 4090 and AMD RX 6900 XT are stellar high-end GPUs, the 4090 performs significantly better across the board, and this performance difference only gets bigger as we move up through resolutions, with the 4090 being almost twice as fast as the 6900 XT at 4K.

Their price difference, which at least currently makes the RTX 4090 $1,500 (68%) more expensive than the 6900 XT, makes all the difference when comparing these two GPUs. Without considering different use cases, we might initially say that the 4090 is worth its extra cost at 4K, and worth it in most cases at 1440p. And both are overkill for 1080p gaming—for most gamers, at least.

But individual use cases need to be considered, too. If you want your games to run at max settings on a high refresh rate monitor at 1440p, a 4090 will get you above the framerates you want in more games. But if you’re willing to drop your settings even slightly, the 6900 XT will get you this in almost any game, too.

At 4K, however, high refresh rate, max setting gaming is only comfortably possible with the 4090. The 6900 XT will struggle with many titles at these settings and this resolution if high refresh rates are your goal. And in the most demanding games it will struggle to hit even 60fps for low refresh rate gaming.

Throw in DLSS and ray tracing capabilities, and the RTX 4090 is a great value offering for 4K gaming. For the first time, 120Hz or 144Hz ultra-high fidelity gaming is possible thanks to the RTX 4090. If that’s what you’re looking for, then it’s probably worth its admittedly astronomical price tag. But if you’re happy dropping settings here and there, or if you’re not using a high refresh rate monitor, the 6900 XT is a much better bet.

Jacob Fox

Jacob's been tinkering with computer hardware for over a decade, and he's written hardware articles for various PC gaming websites. Outside of the wonderful world of PC hardware, he's currently undertaking a PhD in philosophy, with a focus on topics surrounding the meaning of life.

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