Will it be possible to have an AMD APU (such as upcoming Carrizo) and and AMD discrete card (such as the upcoming 300 series)
on one system and be able to use both discrete GPU and integrated GPU, as two separate devices?
Yes, you can use both AMD APUs and dGPUs as different devices, if these devices are supported. With OpenCL 2.0, some of the features may not available on all devices (features like fine grain SVM) and so those would not be available till they are supported.
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