Two (2) GTX 1080 Ti on Gigabyte X299 Aorus for combining 7168 cores under CUDA in Win-10/64

Hello. We have purchased a workstation with the above configuration which will be used for running code written in C++/CUDA for CNN deep-learning. DO WE NEED to bridge the two GTXs with the ‘GTX SLI HB Bridge’ which we can’t anyway purchase it from anywhere as suppliers say that they can’t deliver, or CUDA will recognize them both on the motherboard and will then utilize them both for taking full advantage of the 7168 cores? Thank you very much. John Piliounis, Athens, Greece