Review: AMD Radeon RX 7900 XT and RX 7900 XTX


AMD RX 7900 XT and RX 7900 XTX:


This AMD Radeon RX 7900 XT and RX 7900 XTX are the first two cards that we will test and which benefit from the brand new RDNA3 architecture. This new architecture succeeds RDNA2 which was represented by the last high-end model, the RX 6950 XT. We also reviewed the Powercolor RX 6950 XT Liquid Devil.

The novelty of this architecture is the design based on the addition of MCD (Memory Cache Die), also called memory chiplets. This design with its two distinct parts reminds us of that of AMD processors. We find the GCD (Graphic Compute Die) engraved in 5 nm with a size of 300 mm ² and then five or six MCD (Memory Cache Die) also called memory chiplets that are engraved in 6 nm. Each one occupies a surface of 37 mm².


As you can see on the pictures below, the two boxes are almost identical. The most attentive will notice a slightly different visual that highlights the RGB backlight for the RX 7900 XTX version. The model number is located on the top left of the box whose dimensions are 350 x 185 x 80 mm.

On the back, no technical information but information about the Adrenaline Edition software. We are here on two boxes rather compact and which play on the sobriety. The opening is done by the front side and reveals directly the cards. We can also discover for both models the annotation: ” Welcome to the red team “.

The Radeon RX 7900 XTX version has a little extra since the card lifts up when the box is opened. By visually comparing the two cards, it is easy to spot where the RGB backlight inserts will be on the RX 7900 XTX.

These are the reference cards proposed by AMD as NVIDIA does with its Founders Edition. However, if on the green side only NVIDIA sells its Founders Edition, AMD offers its partners to buy this reference card and then resell it by simply adding their brand.

The cooling :

Our two reference cards have a cooling system consisting of three 92mm fans. The design of both reference cards is visually very pleasing with a touch of RGB backlighting, only on the RX 7900 XTX version. The RADEON logo will not light up when the graphics card is switched on, but the two areas around the central fan. Aesthetically, the two cards look very similar with a slight difference in color for the fairing.

These three fans are responsible for keeping the heat sink in contact with the graphics chip and the various PCB components cool. These fans have 9 blades and will remain at rest when the card is not solicited and conversely, become active again when the temperature requires it. As you can see, the hot air escapes only through the top edge of the board. The bracket is not perforated.

The back of the two cards is protected by an imposing black and rather thick backplate. It is the same on both models. Its role is to avoid the torsion of the PCB but it certainly also plays a role of thermal dissipation with probably the presence of pads between this one and the PCB. As you can see, the backplate joins the fan shroud, which gives the impression that the PCB is enclosed in a shell.

Regarding the thickness, our two samples are on 2.5 slots. The dimensions are slightly different with 276 x 113 mm for the RX 7900 XT and 287 x 123 mm for the RX 7950 XTX. No disassembly of the card since this information is still under NDA. We will have to wait a few more days to discover the radiator and the PCB of these Radeon RX 7900 XT and RX 7900 XTX.

Connectors :

To power these two cards, and this is excellent news, AMD has chosen to keep two 8-pin power connectors. AMD announces a consumption of 300 watts for the RX 7900 XT and 355 watts for the RX 7900 XTX. We also know that concerning the memory, AMD uses GDDR6 instead of GDDR6X for both cards, mainly because it consumes less power and is incidentally less expensive.

AMD has opted for DisplayPort 2.1 support on the RX 7900 XTX and RX 7900 XT. This means higher refresh rate support in 4K and 8K compared to the DisplayPort 1.4 port that NVIDIA uses on its latest RTX 4000 series cards. AMD offers simultaneous encode or decode for AV1, which will be of interest to content creators. So we have two DisplayPort 2.1, one HDMI 2.1 and one USB Type-C port.