A:Answer Depends on what you will be using as source material. If you will be using the Amazon 4k FireTV stick, at worst, you will want to use the extender included with the stick (to avoid overheating issues). For other 4K-based source material, make sure the HDMI cables you use are rated to handle 4k! Also, you can ONLY use HDMI 1 for 4k/HDR-ready material (including the 4k FireTV stick); this applies to all Samsung QLED, CrystalUHD, and UHD 4k HDTVs.