adobe premiere playback lag
Uncompressed 4K video at 60fps requires your playback system to deliver approximately 2GB/sec (or more than 15 Gbps).  You can use Blackmagic Design's Disk Speed Test (part of the Desktop Video bundle you can find here) to see whether your system meets this criteria.  If it does not, then you'll need to compress your video until you have a bitrate that your IO system can actually support.