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Q The HDMI cables I’ve been using with my current TV are now eight years old. I plan to buy a new OLED TV. Will I need new HDMI cables for it? —Jim Stafford / via email

A Not necessarily, though it is possible. Any HDMI cable rated as High Speed, a category that’s been around for more than eight years, should be capable of passing 4K video signals with a frame rate up to 60 hertz. So, if you already own good-quality High Speed HDMI cables, it’s likely that you won’t encounter problems with your current setup when watching movies on Ultra HD Blu-ray or streamed in 4K resolution from Netflix, Amazon, or Vudu.

That said, HDMI 2.0a, the connectivity standard used on new UHDTVs and AV receivers, supports up to 18-Gbps signal bandwidth. Most UltraHD Blu-ray movies are encoded with a 24-Hz frame rate, 10-bit color, and 4:2:0 color subsampling, a combination that requires only 10.2 Gbps. Certain players, however, provide upsampling features to boost color bit depth and increase the color subsampling. When those factors are combined with a 60-Hz frame rate, the player’s output can easily push the limits of HDMI 2.0a’s full bandwidth.

How will you know if your current High Speed cable can handle a full 18-Gbps onslaught? You will see either sparklies (pixel dropouts), an intermittent picture, or no picture at all. And those issues are more likely to pop up with passive HDMI cables having a length greater than 16 feet. How do you deal with the situation? By replacing your cables with a new category called Premium HDMI cables, which are certified by HDMI Licensing to pass signals with full 18-Gbps bandwidth. Premium HDMI cables cost more than regular High Speed versions, but they can provide some peace of mind knowing that your installation will be compatible with all manner of Ultra HD/HDR content.

Related:

HDMI 2.1: What You Need to Know