With two GPUs standard in every Mac Pro configuration, there’s obviously OS support for the configuration. Under Windows, that amounts to basic CrossFire X support.
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Under OS X the situation is a bit more complicated. There is no system-wide CrossFire X equivalent that will automatically split up rendering tasks across both GPUs. By default, one GPU is setup for display duties while the other is used exclusively for GPU compute workloads. GPUs are notoriously bad at context switching, which can severely limit compute performance if the GPU also has to deal with the rendering workloads associated with display in a modern OS.
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Due to the nature of the default GPU division under OS X, all games by default will only use a single GPU. It is up to the game developer to recognize and split rendering across both GPUs, which no one is doing at present. Unfortunately firing up two instances of a 3D workload won’t load balance across the two GPUs by default. I ran Unigine Heaven and Valley benchmarks in parallel, unfortunately both were scheduled on the display GPU leaving the compute GPU completely idle.
To utilize both GPUs in your Mac Pro 2013, ensure that the applications you are running support multi-GPU configuration. Most professional software in video editing, 3D rendering, and graphics design are optimized to take advantage of multiple GPUs. Check the preferences or settings of the application to enable GPU acceleration or multi-GPU support.
Gaming on a Mac Pro 2013 with both GPUs can be limited as macOS is not primarily optimized for gaming, and few games support dual GPUs. However, for games that do support this feature, you can enable it within the game’s settings. Make sure your game and macOS are up to date to maximize compatibility and performance.
You can monitor the usage of both GPUs in your Mac Pro 2013 by using Activity Monitor found in Applications > Utilities. Under the Window menu in Activity Monitor, select GPU History. This will show you a separate window with GPU usage statistics. Third-party applications like iStat Menus can also provide more detailed insights.
Using both GPUs in your Mac Pro 2013 can significantly enhance performance in supported applications, particularly in professional tasks such as video rendering, 3D modeling, and complex computations. This setup allows your system to distribute workload between the two GPUs, leading to faster processing and more efficient handling of graphics-intensive tasks.
Configuration varies by application. For professional software like Adobe Premiere Pro or DaVinci Resolve, you can typically find GPU settings in the Preferences or Settings menu under 'Playback Engine' or 'Video Processing' settings. Ensure that you select an option that enables multi-GPU support. Always refer to the specific application’s documentation for detailed instructions.