AMD Radeon RX 6800 XT tested in Multi-GPU configuration
TweakTown covered a topic of the multi-GPU configuration of the AMD’s fastest (at least for one more day) Radeon RX graphics card.
The Crossfire and SLI technologies might be dead, but the multi-GPU support certainly has not been abandoned. Back in 2015, the news broke that DirectX 12 will allow multi-GPU Explicit Multi-Adapter support, a technology that would allow the mixing of the graphics card from different vendors to work in tandem. This technology required support from the game developers and 5 years later no one is using it.
Soon after that both NVIDIA and AMD have begun killing its multi-GPU technologies, which only generated driver issues and development costs for manufacturers. The current generation of NVIDIA RTX 30 graphics cards only has one model with NVLink fingers, the RTX 3090. This graphics card is so expensive (1,499 USD), that barely anyone had the chance to test it. On the other hand, we have just released Radeon RX 6800 series, which are much cheaper than the flagship Ampere card. Two RX 6800XTs would cost 1300 USD, although this card is nowhere to be found in stock and if they are, they are certainly not sold at this price.
TweakTown tested two Radeon RX 6800 XT graphics cards (one reference and one custom from XFX) in four games and at three resolutions. Those games are heavily based on AMD technologies, so the support for multi-GPU is obviously there. The mGPU support must be enabled through the Radeon Software and it will be visible in TechPowerUP GPU-Z software:
AMD Radeon RX 6800 XT Multi-GPU in GPU-Z, Source: TweakTown
As expected, the mGPU support makes more sense as the resolution increases (4K is heavily GPU bound). Depending on the game settings we are looking at a 101% to 156% performance scaling at 1080p resolution when two RX 6800 XT cards are used. At 1440p Deus Ex the performance even drops to 95% when mGPU is enabled. Overall it appears that Strange Brigade and Sniper Elite 4 are well optimized for mGPU settings:
| AMD Radeon RX 6800 XT multi-GPU Test | |||||||||
|---|---|---|---|---|---|---|---|---|---|
VideoCardz. com |
1080p | 1440p | 2160p | ||||||
| Sniper Elite 4 | 312 | 486 | 156% | 232 | 448 | 193% | 145 | 255 | 176% |
| Strange Brigade | 327 | 433 | 132% | 243 | 404 | 166% | 144 | 278 | 193% |
| Rise of the Tomb Raider | 238 | 277 | 116% | 196 | 272 | 139% | 113 | 204 | 181% |
| Deus Ex Mankind Divided | 134 | 135 | 101% | 124 | 118 | 95% | 70 | 110 | 157% |
The worst-case and the best case for the mGPU support in the TweakTown review:
AMD Radeon RX 6800 XT Multi-GPU: TweakTown
AMD reference Radeon RX 6800 XT and XFX Radeon RX 6800 XT Speedster MERC 319 in multi-GPU configuration.
TweakTown
Source: TweakTown
Test two AMD RX 6800 XT in CrossFire under different games
Hardware
Robert Sole Follow on Twitter Send an email 7 December, 2020
0 3.928 2 reading minutes
The power offered by modern graphics cards makes multi-GPU setups uninteresting. This system has been quite relegated today, but it is still possible to do them without problems. TweakTown colleagues have tried two Radeon RX 6800 XTs in a multi-GPU configuration and they have tested them in games specially optimized for AMD graphics cards.
Both NVIDIA and AMD have left behind the technologies they offered for multi-GPU configurations. NVIDIA for example offers each game developer to support this type of configuration for their graphics. AMD has gradually left CrossFire technology aside and now they are unified under the PCI Express protocol.
| preview | Products | Price range | |
|---|---|---|---|
| XFX RX 5700XT TD | 299,99 EUR | Buy it at Amazon |
This is how two AMD RX 6800 XT graphics perform in different games
To test this configuration we have used the games Sniper Elite 4, Strange Brigade, Rise of the Tomb Raider and Deus Ex Mankind Divided. Under these four games the 1080p, 1440p and 4K resolutions. Where more improvement has been noticed is in 4K resolution, while in 1080p the improvement has been minimal.
The worst-performing game in this configuration is Deus Ex Mankind Divided. Low 1080p resolution the improvement has been only 1%.
as 1440p resolution gives -5% performance and in 4K gets a 57% improvement.
Then we have the Sniper Elite 4 which is the one that offers the best performance under this configuration of two RTX 6800 XTs. Under 1080p resolution it offers a 56% improvement, for 1440p resolution it reaches up to 93% improvement and in 4K it reaches up to 176% improvement. What’s more, for 1080p and 1440p the Sniper Elite 4 is the best performing game, while for 4K it is the Strange Brigade, with an improvement of 93%.
We must bear in mind that this Two AMD Radeon RX 6800XT setup is more expensive than purchasing a RX 6900 XT. We can also see that a multi-GPU configuration may not always offer a great performance improvement.
Complete results
| 1080p resolution | 1x RX6800XT | 2x RX6800XT | Constant improvement |
| Sniper Elite 4 | 312 | 486 | 56% |
| Strange Brigade | 327 | 433 | 32% |
| Rise of the Tomb Raider | 238 | 277 | 16% |
| Deus ex mankind divided | 134 | 135 | 1% |
| 1440p resolution | 1x RX6800XT | 2x RX6800XT | Constant improvement |
| Sniper Elite 4 | 232 | 448 | 93% |
| Strange Brigade | 243 | 404 | 66% |
| Rise of the Tomb Raider | 196 | 272 | 39% |
| Deus ex mankind divided | 124 | 118 | -5% |
| Resolution 4K | 1x RX6800XT | 2x RX6800XT | Constant improvement |
| Sniper Elite 4 | 145 | 255 | 76% |
| Strange Brigade | 144 | 278 | 93% |
| Rise of the Tomb Raider | 113 | 204 | 81% |
| Deus ex mankind divided | 70 | 110 | 57% |
Source: VZ | TT
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