Daily Authority: 💻 USB cable length matters

⛄Good morning and welcome to Tuesday’s Daily Authority. It’s currently -8 here in Scotland, though strangely, that means it’s too cold for snow. I’d rather have the snow!

If you’ve ever wondered just how long a USB cable can be, now’s the time to find out. Our Zak Khan dove deep to answer the question.

“The maximum length of a USB cable depends on which version of the USB standard it’s designed for and whether it’s an active or passive cable. Note that the style of connector, such as USB-A or USB-C, does not necessarily indicate its version or its maximum length. Here are the maximum lengths a passive cable can be depending on the version of USB they’re designed for”:

• USB 1.1: 5 meters (16 feet)
• USB 2.0: 5 meters (16 feet)
• USB 3.0: 2-3 meters (6.5 feet — 9 feet, 10 inches)
• USB 3.1: 3 meters (9 feet, 10 inches)
• USB 3.2: 3 meters (9 feet, 10 inches)
• USB 4: 0.8 meters (31 inches)

Don’t forget that just because a manufacturer claims their cable works with various USB standards, doesn’t necessarily mean it’s true. If a cable’s exceptionally cheap but claims to meet high-speed specs, be wary. It’s always better to buy from a reputable manufacturer with good reviews.

Why is there a max length?

• As well as active and passive USB cables, other factors like the thickness of the cable’s metal conductors are at play.
• If your USB cable’s also sending HDMI, DisplayPort, Thunderbolt, or other signals, that’s also a concern.
• Because passive cables don’t amplify signals, a longer cable means signals sent will be weaker.
• That means if your cable’s too long (or too long and too thin), data loss and slower speeds are likely.
• A longer cable run can also increase the risk of noise from other devices overwhelming data signals.
• Zak explains: “Then there are other, even more highly-technical problems like clock jitter, which start rearing their head the higher speeds and data transfer rates get.”
• With active cables — ones that contain circuitry that amplifies signals — length is slightly less of an issue, as the stronger signals can travel farther without degrading.
• You’ll pay more for an active cable, though, and they’ll sometimes come with their own power supply.

Exceeding the max cable length

You can extend active cables out to a specific level:

• This is usually 30 meters (98 feet) for USB 2.0
• For USB 3.0, 3.1. and 3.2, this is around 18 meters (59 feet).
• Active USB 4 cables are still being introduced but currently reach around 3 meters (9 feet, 10 inches).
• Or you could just use a powered USB hub, which connects to a USB port, and connect your longer cables to the hub.
• If this still doesn’t work for you, check out some of Zak’s other suggestions over in the feature.
• For advice on USB-C cables, check out our guide to USB-C as well as our roundup of the best USB-C cables for charging your devices.

Next time you use a public restroom, we guarantee you’ll think about this…

• We know that toilets spray when flushed, propelling aerosolized poo, water, and even viruses into the air.
• Now scientists at the University of Colorado at Boulder have made this visible.
• The team used continuous and pulsed green lasers and cameras to create a thin, vertical sheet of bright green light aimed at the toilet.
• This sheet lit up and revealed the aerosol spray after a commercial toilet was flushed.
• You can read more about the team’s results in the paper “Commercial toilets emit energetic and rapidly spreading aerosol plumes,” published in Scientific Reports.
• Researchers discovered the “strong chaotic jet” can reach nearly 5 feet (1.5 meters) in height, with a peak velocity of 6.6 feet (2 meters) per second within eight seconds after the flush is activated.
• Larger particles (for the study, this was 5 to 10 micrometers) will fall out of the vapor cloud more quickly.
• Smaller particles can linger in the air or settle on bathroom surfaces.
• Ewww.

Have a great Tuesday!

Paula Beaton, Copy Editor.