Recently, ComputerBase noticed that AMD had taken down slides comparing the performance of its RX 7900 XTX and 7900 XT graphics cards to that of Nvidia's RTX 4090 on a per-watt basis.
According to the presentation's footnotes, AMD was supposed to compare the power efficiency of the RX 7900 XTX and the RTX 4090 in terms of performance per watt on November 15 but never did. The "RX-841" footnote that does not have a matching slide in the deck elucidates the omission. Based on publicly disclosed peak power consumption values (TBP/TGP), the performance-per-watt slide compared the RX 7900 XTX to Nvidia's very power-hungry GeForce RTX 4090. AMD decided to exclude the slide at the last minute after accidentally leaving this footnote in its presentation.
We do not know why AMD decided to remove this slide, and there could be a number of reasons for the omission. First, AMD has stated that the RX 7900 XTX competes with the RTX 4080, so comparing it to the RTX 4090 may have been unnecessary. Furthermore, while Nvidia's 40-series cards consume enormous amounts of energy, the new architecture is more power efficient than its predecessors, and the 40-series cards frequently consume far less energy than the full TGP during gaming.
For example, in our assessment of the RTX 4080, we discovered that the card's performance-per-watt was really good. It outperformed Nvidia's power-hungry RTX 3090 Ti while consuming significantly less power than its maximum 320W TGP allowed during gameplay. We will never know why AMD removed the RX 7900 XTX versus RTX 4090 power efficiency comparison, but one thing is certain: it is gone.