The USB-C Myth: USB-C Cables Can Always Be Plugged in With Either Side "Up"

I may have posted about this briefly before (don't recall for sure), but I thought that this is worth noting because I keep seeing people run into this.

Usually, a USB-C cable or adapter is bi-directional. You can plug in the cable one way, then unplug it, rotate 180 degrees, plug it back in, and get the same result. That turns out to be incorrect for some devices / cables / adapters.

I ran into this when I was using a USB-C to USB-A adapter to connect my SSD to a USB-A port. After doing so, I noticed that I was getting really slow transfer speeds. As I was experimenting, by pure luck, I flipped the cable plugging into my adapter and suddenly had high-speed data transfers. It took me a few seconds, but I suddenly realized what was happening - some adapters are NOT Bi-directional. So, while the USB cable may be capable of plugging in either way, the adapter requires that the USB-C cable be plugged in with one specific orientation otherwise it drops down to USB 2 speeds.

Here is an example of the type of adapter I was using:



Here is what to look for. Make sure that the listing for such a device specifically called out that the device is "bi-directional" or "bidirectional" like in this listing:



Some devices have an LED that will illuminate when you have a high-speed connection. Flip the USB cable and the LED turns off. Here is an image of one such device (a USB-C coupler in this case):



Summary: If you experience slow data rates on HDDs, SSDs, USB Ethernet adapters, etc. trying flipping the USB-C cable. What makes this issue so unintuitive is that the device works - it is just slow.

Over the years, it seems like every, camera or other device that could be connected to a computers USB port had a different connector on the device end, (not the computer end). I got a drawer full of those things, each one different. Likewise Charging cables!

I was talking to a good friend, who I call my Computer Guru, and I asked him if there would ever be a standard charging cable for all cell phones.
And, he said yes, they are doing it now with those little USB-C connectors.
He had his tablet with him and he used my Cell Phone charging cable to charge his tablet. NEAT!

I was really surprised that the connector can be flipped over and still inserts.

Good Topic, and good info! Thank You!

TechnoMage

None of the devices I have with USB-C give any issues about directional plugging.

To add about devices, got a new rechargeable electric shaver few months ago and it came with a cable but no power module. It has the 'special' plug for the shaver on one end of the cable [not USB-C] with a USB-A plug on the other end. The user saves money by using an existing power module and saves traveling space/weight by sharing between the shaver, cellphone, tablet/Kindle or other devices by needing just the one. The shaver was half the cost of my previous shaver that I dropped and broke into pieces.

Berton said:

None of the devices I have with USB-C give any issues about directional plugging.

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The problem seems to be mainly with adapters. As tiny as some of those adapters are I can only speculate that maybe space considerations were an issue, but I don't know that to be fact. It may also just be cheap stuff made in China.

What about the cabling?

Say a male USB 3.0 A on one end, and a male USB-C on the other? Is the USB-C end, flippable regardless of speed?

I use those a lot, especially Samsung ones, connecting external SSDs to my PC or laptop

cheaterslick said:

What about the cabling?

Say a male USB 3.0 A on one end, and a male USB-C on the other? Is the USB-C end, flippable regardless of speed?

I use those a lot of Samsung ones, connecting external SSDs to my PC or laptop

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I guess that it would depend upon the cable. I have not encountered any that were a problem. However, I have been on a quest to try to eliminate as many cables as possible. So, for USB devices I now use EXCLUSIVLY USB-C to USB-C cables and absolutely no other kind of USB cable. If I have a device that requires USB-A, USB-B, micro USB, Mini USB, etc. I use an adapter to adapt the USB-C cable.

I think that I have recycled about 100+ USB cables as a result of this effort.

I now own no other kind of USB cable other than USB-C to USB-C. However, even that is not as simple as it may seem. Some USB-C cables can handle faster speeds than others. Some can provide less power than others. Whenever there is a question, I use a USB 4 / Thunderbolt 4 cable that can provide 240W power, then I am set no matter what .

hsehestedt said:

Whenever there is a question, I use a USB 4 / Thunderbolt 4 cable that can provide 240W power, then I am set no matter what .

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Which ones of those would you recommend?

cheaterslick said:

Which ones of those would you recommend?

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I have no set preference. I typically use cables from companies like Cable Matters and Anker. I know that there are a couple of others I like but I don't recall the brands off the top of my head. If I remember later I will check.

TechnoMage2021 said:

Over the years, it seems like every, camera or other device that could be connected to a computers USB port had a different connector on the device end, (not the computer end). I got a drawer full of those things, each one different.

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Because I rarely use it, I find myself having to dig through my box of USB cables to find one that has a USB type B on one end every time I need one. Getting back on subject, I found out a long time ago that a USB C cable isn't wired exactly the same on both sides and is only reversible when using USB C to USB C. To try and explain what I mean and to make it easy for me to explain I'll just say , a USB C cable isn't wired A,B,C,D,D,C,B,A. The Device has to be wired to use the USB C bi-bidirectionally.

hsehestedt said:

I have no set preference. I typically use cables from companies like Cable Matters and Anker. I know that there are a couple of others I like but I don't recall the brands off the top of my head. If I remember later I will check.

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UGreen is another high-quality maker that I use for both cables and adapters. I too like and use Anker cables and chargers. I also like the high-quality Samsung 8-inch USB C to USB C cables that came with my Samsung portable T7 and T9 SSD drives.

hsehestedt said:

If I remember later I will check.

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Yeah, I'd appreciate that, thanks.

~

I've been finding out that the cables I typically use (male USB 3.0 A on one end, and a male USB-C on the other) wear out quickly and sometimes won't connect. But if I add a new cable to it, it suddenly starts to connect and the problem gets solved. So I know it's a cabling issue and not a drive issue when that happens.

I'm probably using something that's low quality and have throw them out when that happens. What a waste of time and money.

If there's better out there, I wouldn't mind knowing about it. @TraderGary touched on some, already.

cheaterslick said:

Yeah, I'd appreciate that, thanks.

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Here is my list of preferred cable vendors (not in any particular order).

Although I have a lot of cables from KableDirekt, I don't have any USB cables. I think that USB cables may be a newer addition to their lineup. But I've been very impressed with their other cables. They especially seem to be reasonably priced for high quality.

KabelDirekt (NOTE: Have used HDMI and Ethernet cables from these folks but not USB. Everything I tried so far seems very high quality)
Anker (A bit expensive in my opinion)
CableMatters
CableCreation
JSAUX
WOTOBEUS

TraderGary said:

UGreen is another high-quality maker that I use for both cables and adapters. I too like and use Anker cables and chargers. I also like the high-quality Samsung 8-inch USB C to USB C cables that came with my Samsung portable T7 and T9 SSD drives.

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Yeah, I still remember looking everywhere for a charging cable that was rated to 5A just like the one that came bundled with my Huawei P30 Pro phone that I bought new & unused exactly 5 years ago. There was only one cable I could find, as all the other ones were rated to 3A or less so, for 10 Euros on Amazon Germany back then, this is the one I got:



Their wall charger also was the only available one that was noticeably more compact and more lightweight than all the other ones that were compatible with Huawei's proprietary Fast Charge (SuperCharge 40 watts) protocol so, along with the cable, I got it for an additional 12 Euros:



For a 2019 phone with a 4200mAh battery, it charges really, really fast. As a matter of fact both Apple and Samsung were miles behind back then.

TraderGary said:

UGreen is another high-quality maker that I use for both cables and adapters. I too like and use Anker cables and chargers. I also like the high-quality Samsung 8-inch USB C to USB C cables that came with my Samsung portable T7 and T9 SSD drives.

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I agree U-green are good quality.

I find braided cables tend to be more reliable as well.

In the end, if you buy cheap, you pay dear as my dear old gran used to say.

The OPs post is decidely an exaggeration.

Interestingly, I have had other stuff from Ugreen but never a cable. All the other items I had from them seemed to be good quality.

hsehestedt said:

Here is my list of preferred cable vendors (not in any particular order).

Although I have a lot of cables from KableDirekt, I don't have any USB cables. I think that USB cables may be a newer addition to their lineup. But I've been very impressed with their other cables. They especially seem to be reasonably priced for high quality.

KabelDirekt (NOTE: Have used HDMI and Ethernet cables from these folks but not USB. Everything I tried so far seems very high quality)
Anker (A bit expensive in my opinion)
CableMatters
CableCreation
JSAUX
WOTOBEUS

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Thanks for the suggestions. I'm willing to pay more if the quality is better and they'll last longer. The cables I use are typically 6 inches or less.

I never used to think cable quality was a big thing, but as I throw more and more of them out, it's become something critical, especially when your drive won't connect, or suddenly drops off the planet while you're in the middle of something. I don't think it's good for the drive, either.

I'm sure the same wear & tear applies to the USB adapters you started this topic with as well. Having the light on that one particular adapter looks awesome, but I don't know how long that would last. It's a good concept, though...

I connected a Toshiba external drive (USB 3.0) on my laptop (USB-C(USB 3.2 Gen2)) to the USB-C port via a USB-A>USB-C cable(adapter). Always connected as USB 2.0.
Now I tried it on the desktop.
Same external disk and cables, but it connects correctly (USB 3.0).
Any way you want.

cereberus said:

The OPs post is decidely an exaggeration.

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I dont´think so. The problem described is real, but it arises not in USB-C to USB-C cables, but in adapters and converters from USB-C to USB-A that are used in a 10G data link. In these cases, a "double-sided" adapter (with a chip) must be used to ensure transfers at 10G independtly of the connection orientation.

cereberus said:

The OPs post is decidely an exaggeration

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Let's reason on this:

1) If not true, why would so many adapters make a point of advertising that they are bidirectional?

2) Again, if not true, why do some of the adapters provide an LED to indicate that the cable is plugged in with the correct orientation?

3) Finally, I can reproduce this at will all day and all night. Plug in my 2.5Gbps adapter in one orientation and it's slow. Flip the connection by 180 degrees and it is fast. I could do this 100 times and the results would be reproducible 100% of the time.

TechnoMage2021 said:

I asked him if there would ever be a standard charging cable for all cell phones.

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There is one cable for all devices. It comes with different USB tips and even the old iPhone tips so you only need one cable to charge everything. This is what I've been using for the past several years. And you don't even need to plug in the charger. It attaches itself to the device if you just put them closer together. It's called "magnetic charging cable". Just be aware that there are 2 types. One is magnetic data charger (to transfer data from phone to PC) and the other is just a plain charger. The image below supports both charging and data transfer.