Reality Engine supports the GPUDirect technology and it has an additional option to use GPUDirect for accelerating communication with video I/O devices. GPUDirect is an optimized pipeline for frame-based video I/O devices and it maximizes the performance capability of the GPUs. It utilizes the parallel processing power of the GPU for image processing by permitting industry-standard video I/O devices to communicate directly with NVIDIA professional Quadro GPUs at ultra-low latency.
You can also find more information on this link: http://developer.download.nvidia.com/devzone/devcenter/cuda/docs/GPUDirect_Technology_Overview.pdf
You can enable GPUDirect to eliminate CPU Overhead. USEGPUDIRECT property can be found in ENGINECONTROL node under VIDEO I/O category. The below image shows GPUDirect is disabled.
To enable GPUDirect, click on USEGPUDIRECT checkbox. The below image shows GPUDIRECT is enabled.
In Reality Engine, GPU Direct’s default state is Enable. If you run a Project with the DX12 selected and disable the GPU Direct via ENGINECONTROL node, the CHANNEL property of the AJAOUT node becomes read-only, therefore AJAOUT can’t produce any output. To overcome this confrontation, if you are using the DX12 you have to activate the GPU Direct.