Radeon RX 7900 XTX and 7900 XT: AMD attacks Nvidia’s RTX 4000 series

That was a bang that Nvidia should have heard in Santa Clara, 850 kilometers away: AMD presented its new RDNA 3 architecture for graphics chips at the beginning of November as part of the “Together we advance_gaming” event in Las Vegas. And together with her, AMD presented the first two image makers: Radeon RX 7900 XTX and Radeon 7900 XT. And these graphics cards have it all.

The best graphics cards

GeForce RTX 4090 Trinity




Zotac

GeForce RTX 3080 Ti SUPRIM X 12GB GDDR6X


MSI

GeForce RTX 3080 Ti SUPRIM X 12GB GDDR6X

Radeon RX 6800 XT GAMING X TRIO 16GB GDDR6


MSI

Radeon RX 6900 XT Red Devil 16GB GDDR6


powercolor

GeForce RTX 3080 Ti Gaming AMP Holo 12GB GDDR6X


Zotac

GeForce RTX 3090 SUPRIM X 24GB GDDR6X


MSI

GeForce RTX 3080 AMP Holo


Zotac

GeForce RTX 3080 AMP Holo

Radeon RX6800 Nitro+


sapphires

GeForce RTX 3070 Ti AMP Holo


Zotac

GeForce RTX 3070 Ti AMP Holo

GeForce RTX 3070 AMP Holo 8GB GDDR6


Zotac

Complete list: The best graphics cards

RDNA-3 architecture in chiplet design

AMD’s RDNA 3 architecture is not a cautious further development of the RDNA 2 architecture found in the current Sony Playstation 5 and Microsoft Xbox Series X/S game consoles. No, AMD designed number three from scratch. That already starts with the construction. Instead of pressing all the necessary components onto a silicon chip, AMD divides the chip into components. AMD already does this with its processors of the current Ryzen 7000 series. at SsystemOn / A-Chips (SoCs) of smartphones and tablets, this is old hat. Advantage: Depending on requirements, new components such as controllers, graphics memory or entire groups of computing cores can be added for specific applications. This is a new approach for graphics chips.
Radeon RX 7900 XTX and 7900 XT

dr Lisa Su, CEO of AMD, at the RDNA 3 architecture presentation in Las Vegas with the first finished graphics chip.

GCD and MCDs: Separate entities

In the case of the first two chips, Radeon RX 7900 XTX and Radeon RX 7900 XT, this means in concrete terms: AMD divides the graphics chips into several groups, which the manufacturer wires into one unit. On the so-called Graphic Ccomplex DAll the units responsible for the calculations are located here (GCD). In addition, depending on the version, there are different numbers Memory- / Cache-Dies (MCD). AMD places the memory interface, the memory controller and the fast Infinity Cache cache on it. The RX 7900 XTX is 96 megabytes in size, the RX 7900 XT 80 megabytes.

Radeon RX 7900 XTX and 7900 XT

The chiplet design of the RX 7900 XTX: Den Graphic Ccomplex Die (GCD) frame six Memory-/Cache-Dies (MCD).

Different manufacturing processes

AMD places the MCDs around the GCD so that the computing units can access the memory as quickly as possible – this saves a lot of time when accessing. Incidentally, AMD has both units manufactured using different processes at the contract manufacturer TSMC: The memory/cache dies have structures that are 6 nanometers in size, the graphic complex has structures that are 5 nanometers thin.

Radeon RX 7900 XTX and 7900 XT

The Radeon RX 7900 XTX comes with 24 gigabytes of GDDR6 graphics memory.

RX 7900 XTX: 58 billion operations

According to AMD, the chiplet design increases the transistor density by 165 percent. This is how AMD presses on the 300 mm2 small chips of the Radeon RX 7900 XTX and the Radeon RX 7900 XT up to 58 billion circuits (transistors). With the top model Radeon RX 7900 XTX, the manufacturer distributes the circuits to 6,144 stream processors, which AMD in turn divides into 96 compute units, each with 64 stream processors, which are allowed to work at a maximum of 2.5 gigahertz. The graphics memory of the RX 7900 XTX is very generous with 24 gigabytes of type GDDR6, the data exchange between graphics memory and graphics processor takes place via 384 lines (384-bit memory interface).

Radeon RX 7900 XTX and 7900 XT

The Radeon RX 7900 XT has 20 gigabytes of GDDR6 graphics memory.

Radeon RX 7900 XT: 5,376 stream processors

5,376 stream processors work on the currently second strongest model, the RX 7900 XT, which AMD in turn divides into 84 compute units, each with 64 stream processors. The maximum clock frequency is 2.4 gigahertz, the graphics memory of the RX 7900 XT is 20 gigabytes and also of the GDDR6 type. With the 7900XT, data exchange between graphics memory and graphics processor takes place via 320 lines (320-bit memory interface).

Raster Operation Units (ROPs)

5 nanometers / 6 nanometers

Displayport 2.1 (also via USB-C), HDMI 2.1

5 nanometers / 6 nanometers

Displayport 2.1 (also via USB-C), HDMI 2.1

More power for ray tracing

A major weakness of the current RX 6000 series: The performance buckled significantly when ray tracing effects were switched on – for example for an improved display of reflections and shadows. That should now be history. AMD gives the RX 7900 XT 96 separate units for the calculation of raytracing effects of version 2.0, the 7900 XT uses 80 raytracing cores.
Radeon RX 7900 XTX and 7900 XT

Cards with an RX 7900 XTX chip are only slightly larger than the RX 6950 XT, the maximum power consumption is identical.

During the presentation, AMD also repeatedly teased its competitor Nvidia and its new, but problematic power supply connector, which in some cases led to smoke development and scorched cables. According to AMD, this should not happen with the RX 7900 XTX and 7900 XT models. AMD continues to rely on the separate power supply via two 8-pin connectors, adapters are not necessary. The maximum power loss TDP (Thermal Design Power) is 355 watts for the XTX and 300 watts for the XT. AMD therefore recommends a PC power supply with at least 800 watts of power for the 7900 XTX, and at least a 700 watts power supply for the 7900 XT.
Radeon RX 7900 XTX and 7900 XT

Bad to see: Provided you have a suitable monitor, the top model should show up to 480 frames per second when playing in 4K, and 165 frames per second when playing in 8K.

DisplayPort 2.1 with a maximum of 900 Hertz

AMD also promises that both models will have version 2.1 display ports for connecting monitors. The top graphics chip RX 7900 XTX should offer enough power to play games

  • in WQHD (2560×1400 pixels) with a refresh rate of up to 900 Hertz or
  • in 4K (3840×2160 pixels) with a refresh rate of up to 480 Hertz or
  • in 8K (7680×4320 pixels) with a refresh rate of up to 165 Hertz.

Those are big promises. The upcoming tests have to show whether gambling turns into a jerky show. And above all: How hot do monitors run at such high refresh rates? Do they possibly need to cool additional case fans? All pure theory. Because so far there are no monitors that can display such high refresh rates. Samsung wants to show a first model with a new version of the Odyssey G9 at CES in Las Vegas in early 2023 (January 5 to January 8, 2023). More monitors from Acer, Asus, Dell and LG will follow later, says AMD.

Radeon RX 7900 XTX and 7900 XT

Graphics cards with Radeon RX 7900 XTX and 7900 XT are scheduled to go on sale on December 13, 2022.

RX 7900 XTX and RX 7900 XT: prices and launches

The first finished graphics cards with the new AMD Radeon RX 7900 XTX and RX 7900 XT graphics chips are expected to be launched by manufacturers such as Asus, MSI, Powercolor and Sapphire on December 13, 2022. Prices should be $999 for models with the RX 7900 XTX chip, and graphics cards with the smaller RX 7900 XT chip should cost $899. AMD has not yet announced euro prices in Las Vegas.

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