Speed of older Apple HDMI cable

I am of a different opinion. HDMI cables are rated by bandwidth (speed), and it’s the one cable property that matters.

HDMI cables - different cable types - HDMI.org

HDMI - Wikipedia

• The oldest standard (1st generation) was rated 5 Gbps (3.96 for data).
• The next standard was rated 10 Gbps (8.16 for data) (marketed as “High Speed”).
• The next standard was 18 Gbps (14.4 for data) (marketed as “Premium High Speed”).
• The current latest standard is 48 Gbps (42.0 for data) (marketed as “Ultra High Speed”).

It also matters for the the HDMI ports to which it connects. Using 48 Gbps HDMI cable to connect to an HDMI 1.4 port will limit the throughput to the limit of the port (8.16 Gbps). You’ll need devices with HDMI 2.0 ports or better for ~14 Gbps.

Resolution, refresh rate, bit-depth (dynamic range), and chroma subsampling, all influence bandwidth requirements. Just selecting two of those, means assuming some untold value for the others.

If the rated bandwidth is not printed on the cable, and not mentioned on the packaging or invoice, then you’ll have to test, or find the purchase date and someone who knows with what specs it was sold as that time. The old product page for the Store is likely no longer online.

What’s relevant for this discussion is that HDMI.org is about marketing of cables with the org’s specs/logos, which requires licensing i.e. paying them money. A cable can easily meet a consumer’s requirement without the official HDMI logo. Likewise, a cable with the HDMI certified logo can easily not, especially if it’s too long. The responses to OP were made in this context alone.

Lots of vendors including the much beloved Belkin and even consumers prefer to ignore the certification when possible, and both do just fine most of the time in addition to pocketing the savings. Apple doesn’t even sell its Apple-branded cable anymore, doubtless it considers the certification requirement onerous.

The bottom line is that a certified cable is no guarantee of proper operation but yes, it does make it more likely. So, it’s the wtg when buying new. However, if, like the OP, one doesn’t have any information on an existing cable, they need to test the cable for their environment (as I have recommended). Not chuck it because it lacks some gee-whiz logo (which may well be fake, nobody verifies anyway).

Speed isn’t constant - depends on your environment and even there can change in real time. Shorter cables have a better shot at delivering marketed speeds, especially to non-Apple devices. Apple OTOH is a stickler for proper cables and lengths. Lots of ifs and it depends - the only way to find out is to do your own testing.

Cables are not spec’ed by speed (marketed, yes, but not spec’ed). You don’t need this information, they should work fine on your ATV.