What is GPU Transcode?
Simply put it enables an increase in computing performance by harnessing the power of the graphics card to perform tasks that would take significantly longer on a CPU.
As this process requires a significant amount of computational power and is used every second as the player moves around the world the CUDA GPU Transcoding feature offloads much of the work from the CPU to ensure that it is completed as quickly as possible in an attempt to prevent texture streaming and pop-in issues. As the GPU has to also render the in-game graphics the CPU is left with 25-40% of the calculations.
So if u have a 3rd Gen Card such as the GTX250 and above with about 1GB RAM on it u could try and enable this option to improve texture streaming.