Friday, March 29, 2024

AMD Radeon RX 6900 XT vs. Nvidia RTX 3090: Flagship battle

Share

If you want the absolute pinnacle of graphics performance, the RX 6900 XT and RTX 3090 have it, and nothing else comes close. They each have more memory and more raw GPU performance than anything either company has made before. As powerful as they are, though, they have big differences in features and price, which could sway you one way or the other.

It’s time for the most epic of showdowns between the contemporary kings of the GPUs. Which will emerge victorious?

Pricing and availability

The Nvidia RTX 3090 debuted on September 1 alongside the RTX 3080 and 3070. Boasting features that will appeal to workstation and professional owners, it was also marketed as a gaming card and offers the greatest performance of the three. Its price tag was even greater, however, sitting at $1,499 on its September 24 launch date.

If you managed to buy it at that price, you were lucky, because stock was abysmal, and price gouging sent its cost rocketing, reaching at least $2,000 on eBay for even the Founders Edition. That’s likely to remain the case until spring 2021, when Nvidia promises big orders it’s made since will be completed.

The RX 6900 XT was announced on October 28 alongside the RX 6800 XT and 6800. Its price was a far more modest $999. It’s set to be available for sale on December 8, and AMD has taken steps to avoid scalping at launch. Whether that makes a difference for a card that is likely to be extremely popular remains to be seen.

Performance

Comparing core counts between AMD and Nvidia GPUs doesn’t provide much useful information. Although the RX 6900 XT has less than half the stream processors as the RTX 3090 has CUDA cores, that doesn’t mean the 6900 XT is half as quick. We can make more useful comparisons in clock speed and memory.

AMD RX 6900XT
RTX 3090
GPU
TBD
TBD
Interface
PCI Express 4.0
PCI Express 4.0
Cores
4,800 Stream processors
10,496 CUDA cores
Base clock
TBD
1,400MHz
Game clock
2,015MHz
N/A
Boost clock
2,250MHz
1,695MHz
Memory
16GB GDDR6
24GB GDDR6X
Memory speed

19.5Gbps
Bandwidth
TBD
936GBps
Memory bus
256-bit
384-bit
TDP
300w
350w

The RTX 3090 is king on the memory front, with a staggering 24GB of GDDR6X memory. The 6900 XT has a more modest 16GB, though it’s only GDDR6. GGDR6X has bandwidth improvements. However, combined with AMD’s 128MB of Infinity Cache, the RX 6900 XT is able to achieve much higher bandwidth, at least according to AMD’s numbers.

In-game, AMD claims the RX 6900 XT can match the RTX 3090 in most titles. Its benchmarks show an improvement in Forza Horizon 4 and Battlefield V. Some games run slightly worse on AMD’s hardware, though, including Wolfenstein: Young Blood and The Division 2. Manufacturer benchmarks aren’t usually the most reliable, so we’re remaining skeptical until we see third-party results.

Frames per second doesn’t tell the full story. The RX 6900XT is getting some help from Rage Mode — a one-click overclocking utility — and Smart Access Memory in AMD’s benchmarks. Smart Access Memory is a new feature for RX 6000-series cards that allows a Ryzen 5000 CPU and 500-series chipset to utilize the GPU’s ultra-fast GDDR6 memory. According to AMD, using both can offer up to a 13% performance improvement.

AMD didn’t provide benchmarks with these features disabled during its October 28 RX 6000 reveal event. We can guess, though. AMD claimed the cheaper 6800 XT had a 13% performance improvement in Forza Horizon 4 with Rage Mode and Smart Access Memory at 4K. Based on that, we’d expect to see around 150 fps in Forza Horizon 4 with the 6900XT, not 169 fps.

Smart Access Memory is an interesting feature, but it’s niche. Expect slightly lower performance across the board if you don’t have a Ryzen 5000 CPU and motherboard with a 500-series chipset.

Ray tracing, image sharpening, and more

Nvidia has been the only option in ray tracing and A.I.-driven upscaling over the past few years. With the RX 6900 XT, though, that changes. AMD is introducing hardware support for DirectX 12, finally bringing ray tracing features like screen-space reflections and a denoiser to team red. Although AMD was quick to point out these features during its October RX 6000 reveal, the company didn’t provide any performance numbers with ray tracing enabled.

Since ray tracing is a headline feature for the Xbox Series X and PS5 — both of which are powered by the same architecture in the RX 6900 XT — we expect decent performance, at the very least.

Nvidia has pushed hardware-accelerated ray tracing for the past few years, first with RTX 20-series GPUs and now with the RTX 30-series line. The RTX 3090 comes with Nvidia’s new ray-tracing cores, and based on reviews, they help keep frame rates high with ray tracing enabled.

DLSS has been a talking point for team green, too. Nvidia’s A.I.-driven upscaling tech has improved considerably over the past few years, allowing the RTX 3090 to hit 8K near 60 FPS in a range of titles (if you have an 8K display, which, well … you probably don’t). AMD has similar tech inside the RX 6900 XT, though like ray tracing, details are sparse and we don’t have any benchmarks.

Is it time to crown a new king?

At $500 less, we don’t expect the RX 6900 XT to dethrone the RTX 3090 as the fastest consumer GPU. Across games, the RTX 3090 should remain the better-performing card overall. If, however, the RX 6900 XT can get anywhere close, we’ll finally have some competition in the graphics market.

The Infinity Cache and Smart Memory Access are standout features for the RX 6900XT, and if you have the latest AMD tech already, there’s a strong argument to staying in that ecosystem. We’ll need to wait until we see third-party benchmarks to draw any firm conclusions. If the RX 6900 XT performs anywhere near as well as AMD is suggesting, though, Nvidia is in for a tough few years. The RX 6900 XT is $500 more affordable, and when it comes to gaming, it performs as well as the RTX 3090.

Read more

More News