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.
Yes, the Mac Pro 2013 is designed to support dual GPUs and can use both simultaneously for tasks that support multi-GPU configurations, such as certain professional applications and rendering tasks.
Applications that benefit from dual GPU setups include those used for 3D rendering, video editing, scientific simulations, and other compute-intensive tasks. Examples include Final Cut Pro, Adobe Premiere Pro, and DaVinci Resolve.
You can monitor GPU usage using the Activity Monitor application found in the Utilities folder. Additionally, third-party applications like iStat Menus provide more detailed information about GPU performance and usage.
Yes, the Mac Pro 2013 comes with two identical AMD FirePro GPUs (D300, D500, or D700). Having identical GPUs ensures optimal performance and compatibility across applications that can leverage multiple GPUs.
No, the GPUs in the Mac Pro 2013 are not user-upgradable as they are custom-built and integrated into the system. If you require more GPU power, you would need to consider external GPU (eGPU) solutions or upgrading to a newer Mac model that supports eGPUs.