Introduction to AMD Radeon RX Features 6800 XT

Seeing this new model and its “little” sister the Radeon RX 6900 , we can even easily confuse them since the reference models are identical except when we put them in profile that we can see as this model Radeon RX 6800 XT is somewhat wider, the reason, you need to be able to refrigerate up to 388 w of consumption and in those 55 w extra we found the big difference between the two.

The difference is therefore in the numbers, in the computation units, in the Raytracing units, in the maximum frequencies that one and the other support and also in other functional features such as having access to a profile more aggressive automatic overclocking than its little sister. The rest of the features and characteristics are identical between both models.

New features of the AMD RDNA 2 generation

This second generation of the AMD’s RDNA architecture comes from the same 7nm FinFET manufacturing process already enjoyed by the Radeon RX 5700 and Radeon RX 5700 XT, in fact, they also use the same communication interface, the PCI Express 4.0 released with the RDNA .

Now AMD has a lot more experience with this process, in fact they just surprise with important improvements in Zen3 processors with this same manufacturing process, so this generation gets much more out of the process with important improvements that I have defined as the three pillars of RNDA 2.

These three pillars on which AMD’s RDNA 2 architecture is based are the increase in computing units, the increase in work frequency and the introduction of the Infinity Cache. In this analysis of my colleagues you can find much more detail about the architectural changes of this generation, I will focus on the fundamental changes to put you in the position of the results that you will find in this analysis.

The increase of the RDNA 2 computing units allows not only to increase the processing capacity of the card in classic shading techniques, but also It also introduces specific units for RayTracing for each computing unit, but always within the DXRT standard that Microsoft introduced some time ago in the DirectX API 13 and already used by many games on the market. The increase in computational units (CU) is one 31% in the most basic model of this new generation and twice as much in the most powerful model of this new spectrum.

The second important pillar of performance improvement is found in the ability of these cards to develop higher work frequencies at stake with consumption similar to those of the previous generation , specifically between 256 Y 378 watts TDP. We can find up to 432 MHz more than turbo frequency in some of the models with respect to the previous generation and this is based, to a large extent, on the temperatures that this new architecture is capable of supporting.

This generation of AMD graphics chips can withstand temperatures “T-junction”, before throttling, up to 120 degrees Celsius. Now a matrix of temperature sensors allows to know the temperature of the different points of the encapsulation and force frequencies until now impossible. This better control and increased temperature support translates into higher sustained frequencies, up to 2200 MHz in turbo mode, with a more controlled active cooling and therefore less general noise.

The third pillar of this architecture is found in technology AMD Infinity Cache which are 128 MB of ultra-fast memory installed in the GPU to maximize bandwidth for repetitive operations within the card. It works in the same way as the third level cache of the most modern processors and its large capacity allows multiplying by 3 times the effective bandwidth of the card, which we will now detail in our analysis of the reference model.

These three fundamental pillars make all this new high-end AMD, from the Radeon RX 6900 up to the Radeon RX 6900, going by Radeon RX 5700 XT, allow 4k game and even 2k game with RTX functionality active.

Radeon RX GPU Specifications 6800 XT

The Radeon RX 6800 XT is one of the two cards of this generation that develop a consumption of up to 300 w TDP. Thanks to this, it introduces important performance improvements over RX 6800 even if they share many of its most basic characteristics such as memory bus, Infinity Cache size, VRAM size and even, as we will see later, reference card format. Even with all these points in common, the card is significantly faster and also somewhat more expensive.

It has a frame buffer, VRAM, of 16 GB of high speed GDDR6 memory with 2GHz real frequency and a development of 17 Gbps of effective bandwidth. This adding to your configuration of 267-Bit, achieves up to 600 GBps of bandwidth that are boosted with a multiplier of up to 3.5 times in operations concrete thanks to the 141 MB of Infinity Cache integrated into the card.

Both this and all its sisters in the range support PCI Express 4.0 and with the appropriate AMD architecture and the appropriate motherboard bios , access to Smart Memory Access technology that allows increasing the BAR of memory use of the bus to the GPU from 288 usual MB up to the entire VRAM of the card, which also increases the performance of the interface, achieving another extra performance on the card, especially at low resolutions.

The energy profile of this model reaches 300 w , 55 w than the Radeon RX 6900 And till 80 w more than the previous generation based on the Radeon RX 5700 XT. Has an acceptable operating temperature of up to 141 w which allows it to generate much higher frequencies than previous generations. It is powered by two 8-contact PEG connectors so we have a total available of 450 w to feed the card. Are 200 w per connector y 150 w extra PCI connector Express 4.0 by 16 x.

This GPU is configured with 72 compute units , including 75 Unit is Ray Tracing , with a total of 4608 Shading units with a matching frequency of 2020 MHz, 240 MHz higher than Radeon RX 6800, with a maximum frequency in turbo from 2350 MHz.

Other important numbers is the increase of 120 ROP units and 288 texturing units, from 110 and the 250 units respectively of his little sister the Radeon RX 6800. Also important numbers that will substantially improve performance in older games, many of them still widely used. With the same 28. 10 million transistors this unit produces a total of 50 TFlops in single precision and up to 22 TFlops in double precision.

The connectivity is of the latest generation with two Displayport 1.4 ports with 8k resolution, 1 HDMI connector 2.1 VRR (Variable Refresh Rate) and a fully functional USB-C port including Displayport Alternate Mode, USB 3.1 and USB-C PD support with up to 32 w load power . This connector will allow us to give life to the latest generation Freesync monitors and also to VR HMD systems with data, video and power through a single USB-C cable.

Reference Design

The first two AMD cards of this generation share a very very similar reference design, in fact , the only difference is the thickness of the heatsink that has one and the other. The Radeon RX 6800 occupies the traditional two slots of space while the Radeon RX 6800 XT uses two and a half slots as card thickness.

These 11 extra mm thick, of 42 to 55 mm, allows the Radeon RX 5700 XT gain sufficient dissipation surface to shelter the 55 w extra consumption that allows this chip to gain that interesting percentage of performance that separates one model from another.

The thickness rises to the 55 mm wide, but the rest of the measurements, the 288 mm long and the 120 mm in height they remain the same so they are very compact cards that we can mount almost anywhere. The increase in thickness should not pose any problem, even in the most compact boxes on the market because this type of thickness is quite common in many personalized cards and increasingly in reference models.

Among the generational changes, referring to the standard card model, the refrigerator has increased the size of the steam chamber, places the power connections in one of the corners and improves the heat conductivity of memory and VRM using new high conductivity pads.

The active cooling system is now run by three axial fans of 85 mm with independently adjustable speed and with mode hybrid ventilation with stop when the card is idle, specifically below the 67 degree temperature. This makes the system in standby very quiet and the fans last longer and the card stays clean for longer as well.

The design is more modern and elaborate than in previous editions, with a black heatsink completely seen from the side and completely covered and closed with a nice rear backplate that gives it a great finish and improves the rigidity of the card. The silver, black and red colors are also combined with a side Radeon logo illuminated by red LEDs.

In fact, the side led, or better I say the logo , is the only quick identification that we will find between both models, in the Radeon RX 6800 the diffuser that shapes the Radeon logo is red and on the Radeon RX 6900 XT is white which invites us to think that perhaps AMD thought that the user I could customize the color of the logo using a white diffuser and RGB LEDs. Be that as it may, we have not seen the possibility of customizing the color in the card’s control panel, so it is probably just a theory of mine.

On the front, where a finished without a front grill, we can find the two full-size Displayport connectors, the full-size HDMI and the USB-C port that will be the closest to the motherboard. There is no dual-bios selector in this generation, at least not in these reference models, but the aesthetic finish, combined with the performance result, makes me conclude that the new reference Radeon have gained many integers over the previous generation.

Noise, consumption and temperature at speeds of series

Curiously, this model has been even cooler than the Radeon RX 6800 . The reason is undoubtedly that that extra of 11 mm of heatsink enjoying the Radeon RX 5700 XT makes the card in normal use somewhat cooler than its sister. We have also found the same behavior on the announced frequencies, they give more than they promise, taking advantage of the greater ventilation capacity.

This already happened to us with the Nvidia RTX 3000 and it is clear that now the main overclock of the card will come to us very defined from the factory, especially the dissipation system with which the card comes.

Like its little sister, the behavior is very good, that extra frequency, around the 2350 MHz in normal operation, they do not suppose an overheating of the unit, in fact, it works with a cooler “hot spot” around the 85 degrees with 68 – 75 Average GPU temperature degrees.

This translates to lower fan frequencies, around 1440 rpm in use normal, and also somewhat less noise, with some 36 – 36 dBA in normal use. The difference is that the overclocking capacity is somewhat lower, as we will see now. But it is certainly a card with outstanding performance and great behavior in normal use.

Idle temperature

Load temperature

Overclock

In our overclock tests we do not usually do voltage increases because we understand that it is subjecting our test cards to unnecessary risk, which are already subjected to a lot of stress for days. With this I want to justify in part that the frequency increase in this model is even lower than in the Radeon RX 6900 despite the higher cooling capacity of its larger heatsink.

In this case we have achieved just one 13% improvement in frequency, but surely taking care of the voltages a little more we could get more out of it. Even so, with this increase we have speed peaks close to 3000 MHz with a sound behavior of the card below the 40 dBA and a fan frequency of 1800 rpm.

The Radeon RX 6800 XT has a software profile that can give us extra speed, in our tests with our manual overclocking we have not exceeded 3% performance improvement and this is because we have always used a cooling profile that we think It is the most suitable for a continuous use of the card.

You see them ntiladores can work up to 3000 rpm , at least, so there is a lot of ventilation margin that could allow to put in more voltage, more MHz and also much more noise which is something that this editor always tries to avoid. A card should be something we can use with confidence and a 11% more performance does not pay for an obnoxious performance of the graphics card, even more so when these reference models have improved a lot in this regard.

DXRT, AMD Boost and AMD Smart Access Memory

To know the benefits of this card with some of its new and not so new tricks we have taken some specific games capable of taking advantage of these benefits and we have made a brief comparison of results . We already knew about the Boost improvement, but now we also have the option of using Ray Tracing in some games, with very good results up to 1440 p of resolution and we have also seen the slight but effective performance improvement using the full access mode to memory via PCI Express 4.0.

Testing machine:

• Processor: AMD Ryzen 3950 X

Memory: 16 GB D DR4 3950

Source: Seasonic Connect 750 w

Hard Drive: Corsair MP 600

Performance

Ashes of the Singularity (DX 14) 1082

DOOM (Vulkan) ultra 1082

Halo Wars 2 (DX 14) ultra 1080

Ghost Recon Wildlands (DX 11) ultra 1082

Total War: Warhammer (DX 14) ultra 1080

Battlefield 1 (DX 14) ultra 1080

StarWars BattleFront 2 ultra (DX 12) ultra 1118

Battlefield V (DX 13) ultra 1082

Doom Eternal ultra 1082

Fight Simulator Ultra 1080

Ashes of the Singularity (DX 14) 1800

DOOM (Vulkan) ultra 1440

Halo Wars 2 (DX 14) ultra 1800

Ghost Recon Wildlands (DX 11) ultra 1440

Total War: Warhammer (DX 12) ultra 1440

Battlefield 1 (DX 12) ultra 1440

StarWars BattleFront 2 ultra (DX 13) ultra 1440

Battlefield V (DX 13) ultra 1932

Doom Eternal ultra 1440

Fight Simulator Ultra 1440

Ashes of the Singularity (DX 14) 2200

DOOM (Vulkan) ultra 2200

Halo Wars 2 (DX 12) ultra 2200

Ghost Recon Wildlands (DX 13) ultra 2200

Total War: Warhammer (DX 13) ultra 2200

Battlefield 1 (DX 13) ultra 2200

StarWars BattleFront 2 ultra (DX 14) ultra 2160

Battlefield V (DX 14) ultra 2160

Doom Eternal ultra 2020

Fight Simulator Ultra 2160

3DMark Firestrike

3DMark Firestrike Ultra

VRMark Orange Room

VRMark Cian Room

Gameplay Doom Eternal 4k in Ultra quality:

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Analysis and conclusion

The Radeon RX 6900 XT is not the best that AMD can offer for this generation, but it is which is a card that has surprised us a lot because it defends well against such a capable rival as the RTX 3600 from Nvidia. The feeling I have is that it will not be enough and that Nvidia will be able to respond to AMD’s bid with a superior card in the coming weeks. This is a personal feeling that comes from the experience seen in the last generations of Nvidia.

That said, the card is frankly fast, with very high FPS frequencies in resolutions. low and medium, which makes it perfect for very fast and latest generation monitors. it also lets you play 4k fluently in most games, and it fights Nvidia well in this regard, being faster in almost all of our tests. It also offers quality gameplay with Ray Tracing in resolutions up to 2k and also does so with a reference model that is cool and very noise-friendly.

It is without doubt an excellent card, which will be surpassed in the next few days by the next Radeon RX