Gigabyte RX 6900 XT Gaming OC Review

1. Introduction2. Gigabyte RX 6900 XT Gaming OC3. Testing Methodology4. 3DMark Fire Strike & Time Spy5. 3DMark DirectX Raytracing6. Control7. Cyberpunk 20778. F1 20209. Gears 510. Ghost Recon: Breakpoint11. Red Dead Redemption 212. Watch Dogs: Legion13. Clock Speed14. GPU Frequency Response15. Temperatures16. Acoustics17. Noise-Normalised Temperatures18. Power Consumption19. Overclocking20. Closing Thoughts21. View All Pages

Today we are back with our first review of a custom RX 6900 XT graphics card. AMD first introduced the 6900 XT in December last year, but it has taken until now for a custom card to pass through our labs. The model in question is Gigabyte's RX 6900 XT Gaming OC, outfitted with a triple-fan, triple-slot cooler as well as dual-BIOS functionality. How does this compare to AMD's reference design?

We've already reviewed one Gigabyte Gaming OC card this generation, but that was back in November with a look at the RTX 3070 model. Despite that being an Nvidia GPU, and this is AMD, Gigabyte has kept the overall design philosophy very similar for the RX 6900 XT Gaming OC. Emphasis is placed on the large cooler, the choice of BIOS modes, and a minimalistic approach to RGB lighting. The GPU core has also received a slight boost compared to reference spec, with a 35MHz bump to the rated boost clock.

In this review we find out exactly how the two BIOS modes differ while testing power, noise, thermals and more. We also benchmark seven demanding titles to see just how much faster the Gaming OC is compared to AMD's reference card.

	RX 6900 XT	RX 6800 XT	RX 6800	RX 5700 XT	RX 5700
Architecture	RDNA 2	RDNA 2	RDNA 2	RDNA	RDNA
Manufacturing Process	7nm	7nm	7nm	7nm	7nm
Transistor Count	26.8 billion	26.8 billion	26.8 billion	10.3 billion	10.3 billion
Die Size	519 mm²	519 mm²	519 mm²	251 mm²	251mm²
Ray Accelerators	80	72	60	n/a	n/a
Compute Units	80	72	60	40	36
Stream Processors	5120	4608	3840	2560	2304
Game GPU Clock	Up to 2015MHz	Up to 2015MHz	Up to 1815MHz	Up to 1755MHz	Up to 1625MHz
Boost GPU Clock	Up to 2250MHz	Up to 2250MHz	Up to 2105MHz	Up to 1905MHz	Up to 1725MHz
Peak SP Performance	Up to 23.04 TFLOPS	Up to 20.74 TFLOPS	Up to 16.17 TFLOPS	Up to 9.75 TFLOPS	Up to 7.95 TFLOPS
Peak Half Precision Performance	Up to 46.08 TFLOPS	Up to 41.47 TFLOPS	Up to 32.33 TFLOPS	Up to 19.5 TFLOPS	Up to 15.9 TFLOPS
Peak Texture Fill-Rate	Up to 720 GT/s	Up to 648.0 GT/s	Up to 505.2 GT/s	Up to 304.8 GT/s	Up to 248.4 GT/s
ROPs	128	128	96	64	64
Peak Pixel Fill-Rate	Up to 288.0 GP/s	Up to 288.0 GP/s	Up to 202.1 GP/s	Up to 121.9 GP/s	Up to 110.4 GP/s
AMD Infinity Cache	128MB	128MB	128MB	n/a	n/a
Memory	16GB GDDR6	16GB GDDR6	16GB GDDR6	8GB GDDR6	8GB GDDR6
Memory Bandwidth	512 GB/s	512 GB/s	512 GB/s	448 GB/s	448 GB/s
Memory Interface	256-bit	256-bit	256-bit	256-bit	256-bit
Board Power	300W	300W	250W	225W	185W

The make-up of the RX 6900 XT GPU has many similarities to the RX 6800 XT. Still fabricated on TSMC’s 7nm process node, it uses the same Navi 21 GPU, measuring 519 mm². The key difference is that the RX 6900 XT silicon is fully populated, with 80 Compute Units (CUs) compared to 72 for the 6800 XT. This means the flagship chip has an extra 512 Stream Processors, giving a grand total of 5120 shaders.

Rated clock speed is also identical between these two RDNA 2 GPUs. Reference RX 6900 XT has a rated game clock of 2015MHz and a rated boost clock of up to 2250MHz, but Gigabyte has pushed the rated boost clock up to 2285MHz, a 35MHz increase.

AMD has also increased the memory capacity, with 16GB of GDDR6 memory found on every RX 6000 SKU (so far). The memory is clocked at 16Gbps, and operates over a 256-bit memory interface for total bandwidth of 512 GB/s. However, AMD has also implemented a 128MB Infinity Cache on the Navi 21 GPU, to significantly increase effective memory bandwidth without excess power draw.

Speaking of power, the reference RX 6900 XT has a rated total board power (TBP) of 300W. Gigabyte has increased this with the Gaming OC model, to 315W based on our testing, but we look at power draw in more detail later on in the review.

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