Last year, AMD pleased us with a powerful response to the announcement of NVIDIA Ampere video cards, presenting top models based on the RDNA2 architecture. In our reviews, we managed to consider different versions of the Radeon RX 6800 XT and Radeon RX 6800. Now it’s time for a detailed acquaintance with the Radeon RX 6900 XT. The very situation on the market contributes to this, because after a period of wild shortages, older video cards are starting to return to sale. In this review, we take a look at PowerColor’s top-of-the-line Radeon RX 6900 XT, which combines powerful cooling with increased frequency response and ultimate performance.
First, let’s briefly recall the main characteristics of the Radeon RX 6900 XT. This is the older model based on the Navi 21 GPU, where all 80 Compute Units are active. As a result, the Radeon RX 6900 XT operates with 5120 stream processors, 320 texture units and 128 ROPs. 80 Ray Accelerator blocks provide hardware acceleration for ray tracing operations. The operating frequencies of the Radeon RX 6900 XT are identical to those of the Radeon RX 6800 XT. Two parameters are declared for Boost frequencies: Game Clock at the level of 2015 MHz and Boost Clock at the level of 2250 MHz. The processor has a large 128 MB Infinity Cash L3 cache. The video buffer is equipped with 16 gigabytes of GDDR6 memory with an effective frequency of 16 GHz on a 256-bit bus. The big plus of the top model is the power at the level of 300 W, which is no different from the Radeon RX 6800 XT. And according to the test results, we will see that the Radeon RX 6900 XT is more economical than the older NVIDIA models.
|Radeon RX 6900 XT
|Radeon RX 6800 XT
|Radeon RX 6800
|Number of transistors, million pieces
|Process technology, nm
|Core area, sq. mm
|Number of stream processors
|Number of Ray Accelerator cores
|Number of texture blocks
|Number of render units
|Base core frequency, MHz
|Game Clock frequency, MHz
|Boost frequency, MHz
|Memory bus, bit
|Memory frequency, MHz
|Memory size, GB
|Supported version of DirectX
|12 Ultimate (12_2)
|12 Ultimate (12_2)
|12 Ultimate (12_2)
|from 50199 UAH
|from 42999 UAH
|from 41999 UAH
Now let’s talk about the PowerColor video card.
PowerColor Red Devil RX 6900 XT Ultimate 16GB GDDR6 (AXRX 6900XTU 16GBD6-3DHE/OC)
In our hands was a model that belongs to the top Red Devil series, and Ultimate in the name hints at maximum performance and high factory overclocking.
This product comes in a large box with a wide range of accessories.
A separate envelope contains instructions and product cards with a QR code for registering and participating in the competition for the best photo with a PowerColor Red Devil video card. There is an adapter cable for connecting the backlight to the motherboard.
The manufacturer not only took care of a support for a heavy video card, but even provided for the possibility of configuring such a support in different ways. When mounting inside a conventional housing, you will need an adjustable foot option where you can change the position of the rubber-coated support “foot”. If necessary, the support can be increased by a second block.
Before us is a large video card with a length of 32 cm, which has become the standard for top models from AMD and NVIDIA. The weight is 1.6 kg, and this is not much compared to some GeForce RTX 1.9 kg.
The video card occupies three slots, the thickness of the device is 62 mm. The massive radiator is covered with a metal casing with three fans.
The reverse side is covered with a backplate.
The plate has an illuminated Red Devil logo. On the side where there is no board, slots are provided to reduce the resistance to air flow inside the case. Power is connected to three eight-pin connectors.
In the opposite corner is the BIOS switch. The video card has two firmware with different frequencies and different fan speeds — OC and Silent modes. By default, the OC performance mode is enabled, and we will consider it the main one.
Even with an external examination, the cooling system looks very solid thanks to a massive radiator.
As befits a top product, the PowerColor Red Devil RX 6900 XT Ultimate comes with RGB lighting. Illuminated inserts on the back of the case and the logo create a bright red illumination inside the case.
The Devil Zone RGB app allows you to change the glow mode. To control the backlight and synchronize it with the motherboard, an additional cable connection is provided.
There are three DisplayPort ports and one HDMI on the rear panel. Additional illumination of the connectors makes it easier to connect when you need to crawl under the table to plug in the cable.
PowerColor uses a single heatsink for all elements. For contact with transistors and chokes of the supply circuits, large contact pads are provided.
The large base draws heat away from the GPU and memory chips. It is worth noting the high quality of processing and the flat surface of this base and all areas on the radiator.
Five heatpipes provide heat distribution across two sections of plates. On top of the heatsink is a thin mounting frame to which three fans are screwed.
The diameter of the impeller of the side fans approaches the full 100 mm, while the diameter of the central one does not exceed 90 mm. They have large blades, but in general they do without any unique structural elements such as the outer ring, etc.
PowerColor engineers took the basic reference design as a basis and beefed up the power system.
If the standard Radeon RX 6900 XT has 16 power phases, then the PowerColor Red Devil already has 19 (16 on the GPU).
The Navi 21 processor powers all 5120 stream processors for maximum computing power.
Samsung K4ZAF325BM-HC16 memory chips are soldered, the video buffer size is 16 gigabytes.
PowerColor Red Devil RX 6900 XT Ultimate operates at higher frequencies. The base frequency has been increased from 1825 to 2050 MHz, the Game Clock has been increased from 2015 to 2235 MHz, and the Boost Clock has been increased from 2250 to 2425 MHz. The data exchange rate for GDDR6 memory is at the standard level of 16000 MHz.
The specified characteristics correspond to the OC mode. Max Boost point 2600 MHz. Real frequencies in games are closer to the range of 2350-2420 MHz. The 3DMark Time Spy stress test reached 73°C with a fan speed of up to 1870 rpm, while the Godfall continuous load with tracing reached 74°C with a fan speed of 1800 rpm. Testing was carried out in an open case at 26 °C indoors.
These are excellent thermal and noise characteristics for a top-end factory overclocked video card, especially against the backdrop of NVIDIA’s hot GeForce RTX 3080 Ti. However, the temperature of the hottest point of the Hot Spot crystal is almost 20 °C higher.
Switching to Silent firmware lowers the Game Clock to 2135MHz and the Boost Clock to 2335MHz.
In the 3DMark Time Spy stress test, the fan speed dropped to 1560 rpm with an increase in operating temperature by one degree. Changes in frequency dynamics are barely noticeable, but the results in 3DMark tests are 1.7% lower.
The initial frequencies of PowerColor Red Devil Ultimate are at the same level as that shown by the overclocked reference design AMD Radeon RX 6800 XT. Additional acceleration allows you to squeeze even more. For this, we exclusively used the software tools available in the GPU setup menu in the standard AMD software suite. Our final settings configuration is shown below.
Base frequency 2120 MHz with Game Clock 2400 MHz and Boost up to 2680 MHz. It was not possible to raise the memory frequency above 2180 (17440) MHz, high frequencies led to a drop in results or rare image artifacts. In general, this is standard behavior and many RX 6800 series graphics cards are unstable at 17600 MHz memory clocks. Power Limit increased to maximum, increased fan speed for better cooling.
The average Boost in games has grown to 2440-2500 MHz. With our settings, the fan speed was kept at around 2800 rpm with GPU temperatures up to 75 ° C.
Increasing the frequencies leads to a serious increase in heat release. To maintain acoustic comfort, you will have to carefully select the frequency configuration, which will only slightly exceed the factory settings.