Not so long ago, we wrote a piece provocatively titled "Why all HDMI cables are the same". There was a ruckus, which we expected.
But the post also generated some great questions. So let's take a look at some of the more common and persistent questions from the initial article, and flush some more of the myths surrounding the decidedly-not-magic HDMI cable down the drain.
Is it true that all HDMI cables are the same?
Forgive us our bit of sensationalism in the title. Of course, two cables from different manufacturers are likely to be physically different, although every branded or no-name HDMI cable comes from only a handful of Chinese manufacturers. The picture quality, though, is going to be the same. Because of how the HDMI technology works, it's not possible for the cable to do anything to the picture but make it disappear.
If the cable is defective, you're likely to get no picture or "sparkles", which look like white dots or snow. If you get this, return the cable; it's broken. If you're getting an image, it's exactly what your Blu-ray player, Foxtel box or free-to-air receiver is sending, 100 per cent.
If you think you're seeing sparkles, there are a whole bunch of images showing sparkles in the original article.
I need to run 30m of HDMI cable through my walls to a TV in my bedroom. Are you really saying I only have to spend $50?
Well ... sort of. We did some testing on cheap, long HDMI cables. The more expensive cables were more likely to transmit the data over long runs with a wide range of equipment.
Before a bunch of you scream "Ha! See!" and chuck your mac and cheese at the PC, let us explain. When the cheaper cables worked, they looked exactly the same as the expensive cables. It's just that the expensive cables were more likely to transmit all the data. Some of the cheap cables would either have sparkles or not have any picture at all. Sometimes, they would work with some equipment, but not with others — for example, with one TV, but not another, or from one Blu-ray player but not another.
Regardless of what you choose, it is vital to test the cable before you run it through walls. Even if you do this, if you change equipment (TV, receiver, Blu-ray player, whatever), the cable may not work.
One possible trick, though, is if you're only running cable TV or free-to-air TV , you're only sending 1080i max. All of the cables we tested could handle 1080i easily. Even 1080p/24 is easily transmittable. It's 1080p/50 that's tricky. Thankfully, there are very few sources that are 1080p/50 — games, really, and some concert Blu-rays.
There are four types of HDMI cables for the home, and only four types:
- High speed (Category 2)
- Standard speed (Category 1)
- High speed (Category 2) with Ethernet
- Standard speed (Category 1) with Ethernet.
Standard-speed HDMI cables are rated up to 1080i. They might do more than this, but they're just rated for 1080i. High-speed HDMI cables are rated well above 1080p, which is the maximum possible resolution from your Xbox 360 or PS3.
Even 3D doesn't require more than what's possible over a cheap high-speed HDMI cable. You can buy a high-speed HDMI cable for a couple of dollars, so just buy that and don't worry about the rest.
You're an idiot!
You have no idea.
I bought an (insert expensive brand name here) HDMI cable, compared it to the one I got for free with my DVD/Blu-ray player and there was a huge difference. You're an idiot.
Do you know that last guy? Interestingly, we also got letters saying the exact opposite, that they bought a better cable, saw no difference, so they returned it. There are two potential possibilities at play here.
The first is flawed testing. We recently did an article about the problem with A/B comparisons. If your testing methodology is flawed, you can get all sorts of weird results. Without being in the room, we don't know what you saw or how you tested it. Maybe you did see something, but it wasn't the cable.
There's also the problem of expectation. Having just blown $100+ on something, most people want it to work, so they'll see what they want to see. We all do this. The virulence of some of the comments on the original article was hardly surprising. People don't like being told they're wrong or got ripped off.
I was told I needed a special HDMI cable for my new 200Hz LCD TV to work.
Never buy from that store again. You were lied to, either maliciously or by someone who has no idea what they're doing. Either way, avoid them. The maximum resolution possible from any consumer equipment is 1080p/50 (which, as mentioned above, is rare). That 1080p/50 is converted by the TV internally to 100Hz, 200Hz or whatever. All that's ever transmitted over HDMI is 1080p/50 from your Blu-ray player or 1080i from your cable/free-to-air/PVR box.
In theory, if you have a home theatre PC, it could output more than 1080p/50, and a high-speed HDMI cable could transmit that higher resolution and frame rate to the TV. But why would you want to? The TV, if it accepts that higher rate (it probably won't) will just convert it back down to 1080p/50 and then up again to 200Hz.
All HDMI cables can handle 1080i. High-speed (Category 2) cables are rated up to 4096x2160 (or 4K) at a progressive 24 frames per second. In other words, even if you buy one of Sony's new 4K projectors for US$25,000, your $5 high-speed HDMI cable is rated to carry all that resolution.
Got more questions for Geoff? Feel free to message him on Twitter @TechWriterGeoff.