SLI / CrossFire Bridges for Graphics Cards
Giving way for multi-GPU configurations for increased performance, gamers will require a GPU bridge in order to make use of the technology. Known as SLI for Nvidia GPUs and CrossFire for AMD GPUs, SLI / CrossFire bridges allow two or more graphics cards to synchronize gaming performance and deliver improvements that scale according to the number of installed graphics cards. For both AMD and Nvidia graphics cards there are a number of differences for how each GPU can be installed, and how well each manufacturer makes use of the technology. Since the purpose of multi-GPU configurations is to provide an increase in performance, support from both the graphics card manufacturers and the game developer must be there in order to make efficient use of the software.
While there are a large number of games which will take full advantage of the technology, there are a few number of games that will not support it. For the games that do, gamers can expect upto twice the performance gains when using two GPUs, with on-going support through GPU drivers to further increase their performance. Although the technology functions by synchronizing multiple GPUs, which essentially increases the amount of power that’s available for rendering the game, the amount of VRAM does not increase since the GPUs function as a mirror. As the technology continues to improve and game development continues to make efficient use of multi-GPU configurations, game developers will be making further adjustments to the manner in which VRAM is used. This is something that’s fairly new, and as of such, the unification of total available VRAM is beginning to gain traction.
Gamers looking to increase the performance of their Radeon GPUs can do so in a variety of ways. Those with an AMD 200 Series GPU may require a CrossFire bridge depending on the GPU they own. These graphics cards consist of the R7 265, R9 270, R9 270X, R9 280 and the R9 280X. For owners of a R9 290, R920X or R9 295X2 will not require a CrossFire bridge in order to make of multi-GPU configurations. These feature remains true for R9 300, RX 400 and RX 500 series GPUs. As the multi-GPU configuration requires identical GPUs to be installed, gamers are given choice in which custom graphics card they purchase from 3rd-party vendors. This allows graphics cards from both Sapphire, Gigabyte, MSI, Asus and so on to be installed simultaneously, as long the GPU remains the same.
Giving way for a maximum of upto four graphics cards to be installed in one PC, AMD GPUs can take full advantage of multi-GPU configurations, allowing gamers to increase their performance as they see necessary and style each GPU to their own accord. Along with the Radeon graphics technology featured on AMD APUs, gamers can combine the power of their discrete graphics card with the APU to further increase their performance. In order to enable AMD CrossFire, the desired number of graphics card must be installed, then enabled through the AMD Catalyst Control Center.
Allowing gamers with Nvidia GeForce GTX series graphics cards to utilize the power of multiple GPUs, Nvidia SLI differs slightly from the AMD based solutions while still providing the same increase in performance. Owners with the latest GeForce 10 series GPUs can install upto two Geforce GTX GPUs for upto twice the performance increase. For those who own Nvidia 900 series GPUs or prior, a maximum of four GPUs can be used in a multi-GPU configuration. In order to enable SLI functionality, the graphics cards must be installed in the system and connected with a SLI bridge, then enabled from the Nvidia Control Panel.
Nvidia’s solution to multi-GPU configuration requires two identical GPUs, and just like AMD’s solution, GPUs can be used be from any 3rd-party vendor. Where Nvidia differs from AMD in terms of feature-set is down to the manner in-which multi-GPU configurations can be used for more than just an increase in performance. Allowing gamers to install upto four GPUs depending on which GeForce GTX series the gamer owns, non-identical GPUs can also be used for the purposes of Nvidia’s GameWorks features.
For games which feature Nvidia’s proprietary PhysX software, gamers assign the secondary GPU to process the software while the primary GPU renders the game. As PhysX is a software developed by Nvidia which gives developers the means to create physics-based simulations for aspects such as smoke, snow, particles, rain, dust, cloth and environmental destruction, the use of a secondary GPU to process these complex effects can provide a substantial benefit.