slots. This also allows for four-way SLI using only two cards (which is referred to as Quad SLI). Nvidia has created a set of custom video game profiles in cooperation with video game publishers that will automatically enable SLI in the mode that gives the largest performance boost. Nvidia has three types of SLI bridges: Standard bridge (400 MHz pixel clock and 1 GB/s bandwidth) LED bridge (540 MHz pixel clock) High-bandwidth bridge (650 MHz pixel clock and 2 GB/s bandwidth) The standard bridge is traditionally included with motherboards that support SLI and is recommended for monitors up to 1920×1080 and 2560×1440 at 60 Hz. The LED bridge is sold by Nvidia, EVGA, and others and is recommended for monitors up to 2560×1440 at 120 Hz and above and 4K. The LED bridges can only function at the increased pixel clock if the GPU supports that clock. The high-bandwidth bridge is only sold by Nvidia and is recommended for monitors up to 5K and surround. The following table provides an overview on the maximum theoretical bandwidth for data transfers depending on bridge type specifications as found on the open market: SLI modes Split frame rendering (SFR) This analyzes the rendered image in order to split the workload equally between the two GPUs. To do this, the frame is split horizontally in varying ratios depending on geometry. For example, in a scene where the top half of the frame is mostly empty sky, the dividing line will lower, balancing geometry workload between the two GPUs. Alternate frame rendering (AFR) Each GPU renders entire frames in sequence. For example, in a two-way setup, one GPU renders the odd frames, the other the even frames, one after the other. Finished outputs are sent to the master for display. Ideally, this would result in the rendering time being cut by the number of GPUs available. In their advertising, Nvidia claims up to 1.9 times the performance of one card with the two-way setup. While AFR may produce higher overall framerates than SFR, it also exhibits the temporal artifact known as micro stuttering, which may affect frame rate perception. It is noteworthy that while the frequency at which frames arrive may be doubled, the time to produce the frame is not reduced – which means that AFR is not a viable method of reducing input lag. SLI antialiasing This is a standalone rendering mode that