At TNC16 conference we have demonstrated a transmission of live, JPEG compressed 8K video connecting Poznan and Prague implemented using the UltraGrid software over Géant network. We continue with the development of the UltraGrid towards supporting transmissions of uncompressed 8K video. Uncompressed 8K video at 60 frames per second introduces a bitrate of about 33Gbps. Our implementation of uncompressed 8K video transmission in UltraGrid still relies on commodity PC platform stressing the need for software optimization of the transmission namely in terms of stream throughput through different components of the PC architecture. In the poster we'll discuss the necessary hardware and software optimizations needed to implement uncompressed 8K video transmissions using UltraGrid on the commodity PCs. 33Gbps of stream bitrate orderly matches the capacity of recent NREN backbone networks connected through the Géant network. These network links are usually heavily used by regular users traffic and by large data transmissions. This cross-traffic uses bandwidth comparable to the bandwidth needed by a single stream of above described 8K video transmission. Under such conditions it is not completely possible to transmit and receive uncompressed video streams especially over cross-border backbone links without significant packet loss. We are convinced that the solution to this issue is deployment of Software Defined Networking allowing reservation of end-to-end circuits with defined bandwidth. One issue is the availability of 40Gbps network links at the end-user campuses or laboratories, the other is the availability of Software Defined Networking enabled hardware. We'll discuss the state of deployment and experiments within 8K video transmissions within the CESNET network connecting the SITOLA and SAGELab laboratories and reaching out to the Géant network allowing for international transmissions of live, uncompressed 8K video.