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4K and UHD: What’s the Difference?

Posted by admin on August 20, 2015 10:13 am

The similarities in resolution between 4K and UHD has led to much confusion for both businesses and consumers. Most TV monitors and computer screens that advertise themselves as 4K would more accurately be called UHD. To add to the confusion, many companies are mashing the two together and marketing their displays as 4K/UHD (or 2K/4K UHD, which indicates that it is downward compatible).

What’s the Difference?

While the difference between the two is subtle, a distinction can be made between the two by examining the resolution and the pixel range offered by each. The 3840 x 2160 pixel resolution commonly adopted by 16:9 ratio televisions would be deemed UltraHD, while the resolution more often used in digital cinema (4096 x 2160 pixels) should be called 4K. So technically the term 4K is inaccurate when discussing the standard for broadcast and consumer displays—UHD would be the proper term. 4K would then be reserved as the standard for cinema and professional productions. Unfortunately it’s not gone that direction for marketing reasons so, when you see 4K or 4K/UHD being used, pay attention to the resolution in the details.

Now that we’ve made the distinction between the two, let’s take a closer look at how they stack up when transferring data.

Data Transfer & Switching

4K/UHD content can be sent via Ethernet/IP, copper (typically HDMI), or fiber, provided that the user has hardware capable of handling the data transfer.

Fiber and HDMI works for point-to-point distribution whereas the benefit of IP is that it more readily allows for point-to-multipoint scenarios. However, splitters and matrix switches can be used to optimize the network design and make switching between streaming or hard-wired transfer possible.

Fiber optic cables can transmit 4K/UHD data further than any other option and is used most often in commercial sectors. Currently 10 GB fiber backbones are being used for broadcast TV distribution over long distances, as well as, in post-production and digital cinema. However, fiber has yet to be implemented on a large enough scale to make it a viable option for many consumers. Although some areas are already benefiting from the “fiber to the home” (FTTH) push of providers such as Verizon and Google.

Fortunately, standard HDMI 1.4 cables can send 4K, delivering a 3820 x 2160 resolution at 30 frames per second. There has been some debate over the benefit of higher-end HDMI cables for 4K streaming, but most distributors recommend using the cables you have and later upgrading to HDMI 2.0 cable for transmission rates of 60 frames per second. Connecting of a PC to a monitor can also be done with a DisplayPort cable capable of carrying 4K video/audio/data from your graphics card, with little noticeable delay.

The ability of your devices to stream your 4K content will depend on what type of Ethernet/IP network you’re using. If you’re using a Cat5 Ethernet cable with a maximum of 10 Mbps, you’re probably out of luck. A Cat5e or Cat6 may be able to do the job though, if you have the option, Cat6a or Cat7 would be the wisest choice for 10GB 4K/UHD streaming.

Using HDBaseT optimized equipment gives you the versatility to utilize HDMI cables for shorter runs and then extend the transmission over much longer distances, up to 100 meters (nearly 330 feet), over Ethernet cabling. It is optimized for distributed video, audio, data, power (100 watts) and control signals, cutting down on costs by requiring fewer receivers, power supplies and sources for your video output. Although HDBaseT uses the same Cat5e or higher cables used by IP systems, it is uncompressed and serialized rather than the compressed packet data used with Ethernet transmission.

How Does CATx/HDBaseT Compare to CATx/IP When Transferring Data?

The first challenge to consider is bandwidth and Internet speed—4K is a lot of information to handle. Many basic connections can barely handle streaming HD 1080P now, and we are looking at sending 4 times that amount of data, requiring a downstream connection of at least 15-25 Mbps. Video compression technologies have improved this somewhat, but more compression lowers quality in order to increase transfer rates, which may defeat the greater picture quality that we are looking to achieve. The resolution difference between 4K and UHD is almost negligible—most users will find that the limiting step for their ability to stream such content is the size of their pipe rather than any inherent difference in video resolution.

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Topics: 4K Video

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