I've used 4k on Prime and also on iPlayer. The iPlayer stuff was this year's Wimbledon and their UHD test streams. Wimbledon was about 38Mbit/sec as measured by my ISP, so essentially raw bits on the line. The BBC UHD test streams come in at about 23MBit/sec, the difference being that they can afford to do a lot more processing in the encoding for recorded stuff versus live. 4k on Amazon is around 15MBits/sec.
Biting the hand that feeds IT
