AMD Radeon RX 6800 XT vs AMD Radeon RX 7900 XT

AMD Radeon RX 6800 XT

The AMD Radeon RX 6800 XT is a high-desktop GPU based on the RDNA2 architecture and uses the Navi 21 chip which is manufactured in 7nm at TSMC. The GPU has 4,608 shader units, as well as 16 GB of GDDR6 VRAM with a 256-bit interface (16 Gbps, 512 GB/s).

Features.
RDNA2 serves as the basis for the Navi 21 graphics chip, which is the successor to the Navi 10 graphics chip from the previous RX 5700 series. A number of new features like SAM (Smart Access Memory) and the Infinity Cache make the RX 6800 series very interesting. PCI Express 4.0 and RIS (Radeon Image Sharpening) are still available. The new Media Engine lets you decode video at up to 8K resolution, and the new Display Engine supports screens up to 8K at 60Hz including HDR or 4K HDR at 144Hz. 

Performance.
The performance of the AMD Radeon RX 6800 XT is comparable to a Nvidia GeForce RTX 3080. In the internal duel, the RX 6800 XT clearly surpasses the performance of a Radeon RX 5700 XT. This makes the RX 6800 XT suitable for 4K gaming.

Power consumption

The power consumption of the AMD Radeon RX 6800 XT is quantified by the manufacturer at 300 watts (TGP) and is thus somewhat more economical than the GeForce RTX 3080 (320 watts).

AMD Radeon RX 7900 XT

The AMD Radeon RX 7900 XT is a high end desktop graphics card based on the RDNA 3 architecture. It uses the Navi 31 Chip with consists out of a Graphics Compute Die (GCD) manufactured in 5nm and five (out of six) Memory Cache Dies (MCD chiplets) in 6nm. The 7900 XT offers 5.376 cores clocked at up to 2.4 GHz (max, 2 GHz game average), 80 MB Infinity Cache (L3 cache) and 20 GB GDDR6 graphics memory with a 320 Bit memory bus and 20 Gbps effective speed.

The average gaming performance is slightly below the GeForce RTX 4080 in games (without raytracing). Therefore, the RX 7900 XT is best suited for QHD (for higher frame rates) up to 4K resolution and maximum detail settings of 2022 games. Raytracing performance is still a bit lower than with Nvidia cards, but a big step up from the previous generation.

The integrated video en- and decoders support AV1, H.264, and HEVC videos wit up to 8K resolution. The display ports are a big advantage of the new chip supporting DisplayPort 2.1 with UHBR13.5 for up to 54 Gbps bandwidth (up to 8K 165 Hz with DSC possible).

The power consumption is rated 315 Watt and in our tests similar to the RTX 4080.