AMD Radeon RX 7900 XTX and RX 7900 XT: 70% faster graphics cards in games

If the time is not yet for the great technical unpacking of the RDNA 3 architecture which is at the heart of the Radeon RX 7000 GPUs, AMD has nevertheless taken advantage of the official presentation of its new series of graphics cards to draw up the outlines. technical and, as expected, a fairly significant generational leap is expected compared to the Radeon RX 6000s.

The new graphic architecture used on these chips would, according to AMD, give the opportunity to observe a gain in the energy ratio of 54%, much helped by the switch to 5 nm engraving. Two types of engraving are also on the program, AMD also using 6 nm for the 6 memory modules (MCD, 6x 37mm2) which take place around the graphics chip itself (GCD, 300 mm2), the whole being then placed on a single physical module named MCM (multi-chip module). An approach similar to what the firm has been offering with its Ryzen for several years.

The whole results in a chip with 58 billion transistors, almost double the previous generation, but well below the 76.3 billion transistors of the GPU of the GeForce RTX 4090. Physically, the chip is not not to mention the Radeons using HBM memory. However, here it is indeed GDDR6 memory that is used and placed on the card’s printed circuit – AMD having preferred this technology to GDDR6X, considering the energy/cost ratio more advantageous over GDDR6. The MCD modules actually contain the Infinity Cache memory and the memory controllers. As a reminder, the Infinity Cache was implemented on the Radeon RX 6000 and is to be seen as an extremely fast and energy-efficient buffer memory, allowing processing to be accelerated under certain conditions.

Inside the GPU, AMD has revised a large part of its calculation units with an approach closer to that of Nvidia. In particular, there are units dedicated to the acceleration of AI-related processing, new units dedicated to the acceleration of raytracing announced as 50% faster and classic units with doubled throughput.

The move to 5 nm on the GCD allows AMD to accommodate an increased number of computing units: 96 CUs or 6144 units on the Radeon RX 7900 XTX and 84 CUs or 5376 units on the Radeon RX 7900 XT. The Radeon RX 6950 XT only has 5120 as a reminder, but the RX 7900s on the other hand have a double output on these units, allowing somewhere to see them as “doubled”. The frequency moves only slightly, with a maximum of 2.3 GHz. The graphics memory is 20 GB on the XT version and increased to 24 GB on the high-end XTX version.

In terms of appearance, AMD has slightly revised the curves of its graphics cards but remains on an ultra classic design. Three fans cool the heat sink (which has a vapor chamber) by pushing air over it. A system that has the merit of being able to operate without making too much noise.

If an increase in power consumption is clearly on the program, the difference compared to the Radeon RX 6000 is not as marked as that between the GeForce RTX 30 and RTX 40. It is thus necessary to count on 355 watts for the 7900 XTX model and 300 watts on the lower declination. The power supply also goes through two classic 8-pin connectors, AMD not having chosen to switch to the PCIe 5 12 HPWR connector, a choice probably wise given the setbacks observed on this connector which equips the GeForce RTX 4090. he interface, on the other hand, remains on PCIe 4, AMD having indicated to us that the cost/benefit ratio for the user of PCIe 5 is not, for the moment, judicious.

The part related to multimedia is also evolving with the arrival of DisplayPort 2.1 in the first place. A first on the market that allows AMD to offer a video output capable of processing an 8K signal at 165 Hz, 4K at 480 Hz and 1440p at 900 Hz. The first DisplayPort 2.1 compatible screens are expected in early 2023 – announcements should be made at CES – including Samsung and its Odyssey Neo G9.

The video encoding and decoding engine is also up to date. Doubled, as on the RTX 40, it is now able to accelerate video streams in AVC, HEVC or AV1 formats, both in encoding and decoding.

What about performance in games? For the moment, AMD has been rather stingy with information. On average, the firm announces that the Radeon RX 7900 XTX is 70% faster than the Radeon RX 6950 XT when used on a 4K monitor. A fairly significant generational leap it must be admitted, especially since it concerns both rasterized games and those executed in raytracing. Activating the FSR also allows you to play games in 8K or 8K Ultra Wide at rather interesting speeds, but on titles that do not use raytracing.

The Radeon RX 7900 XTX and Radeon RX 7900 XT will go on sale December 13 for $999 and $899 respectively. Higher prices than on the old generation, but which place them well below Nvidia’s GeForce RTX 40 ($1,199 for the RTX 4080 and $1,599 for the RTX 4090). AMD has not given any indicator on the performance to expect against the new Nvidia cards, we are now looking forward to being able to test them in order to see a little more clearly as to their positioning in games. Finally, regarding availability, AMD hopes to be able to meet demand and has told us that the stock will be real and durable and not limited to the first days of launch.