• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

What kind of a special USB C cable do these new Portable NVMe SSD drives use?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


c(n*199780) Senior Member
Feb 18, 2002
I just purchased the new Crucial X8 portable NVMe SSD. It comes with an (extremely short) cable that is less than 1 foot long.

Okay so if I use any other cable, the transfer speed absolutely plummets.
But when I use the 9 inch original cable it came with to transfer USB C to USB C - it is many (many) times faster than using any other cable.

So where can we buy these "magic" cables? What are they called, are they sold in lengths longer than 0.75 feet!?
I think this is a thunderbolt cable rather than a simple USB-C - the latter ought to work but it won't be as fast. Thunderbolt cables are limited in terms of max. length (IIRC).
Every good quality USB-C cable works fine (exclude cheap, thin cables). I was testing multiple new drives including Crucial X6, X8, Patriot PXD, and some more, on more standard USB-C cables or USB-C with USB-A adapter and all were running fine. When I forget the short cable for my Patriot PXD then I'm using the one which I have to charge my smartphone. At least up to 1-1.5m length, all should be fine. I wasn't testing longer cables.
I look forward to acquiring cables rated for 20 Gbps, or in the case of my Crucial X8 I understand even a 10 Gbps would do. Thank you EarthDog.

So Womack, here's why I started this thread: When I copy/paste, I can clearly see the transfer speed.
Original cable is many times faster than USB to C cables I have, so clearly the cables I have cannot be used with Crucial X8.
So we should look at that for a second.

My "slow" cables do fast charge my Android Galaxy S8, that phone tells you when you connect a cable not capable of fast charging, so the cables I have are standard USB to C cables, which certifiably fast charge Android phones but are, clearly, several times slower when transferring data from new super fast NvMe portable SSD drives.
Of course the test is transferring data from/to superfast NvMe drives, not mechanical drives. So between two fast NvMe drives of course.

I would like to learn more about this issue.
If Crucial X8 and I assume Samsung T7, some of the best selling portable drives on the market today require a 10 Gbps cable, then do any portable SSD drives on the market today require a 20 Gbps cable? My test model is a 1TB Crucial X8. Thank you.

P.S. When is USB 4 cable coming out? Will all USB 4 cables be able to match 10 Gbps or 20 Gbps rates by definition, in other words, if today we have USB C cables that are not powerful enough, does that go away with the new USB 4 standard?
What do unrated standard USB C cables measure?
Answering that feels like trying to assign a rating to a movie deemed 'not yet rated' we haven't seen, lol.

Jokes aside I'm going to assume they vary... hence why a rating isn't mentioned. The next step down in usb world is 5 gbps which would put a glass ceiling on your drive. I'd assume most are slow because you seem to fetch more the higher rating for data and power. So if it could be rated higher it SHOULD be on the box (imo).

I made that same move (external m.2, the adata se900) and just bought a cable rated at 20 gbps as that's as fast as my port (and faster than the drive, which is 2000MB/s gen2x2). If you remember from your USB stick thread, I wanted to make this move and did. :)

Edit: .... my drive is rated for 2000 MB/s... which (if my math is right again), that's about 16 Gbps... so I need a 20 Gbps cable and 3.2 gen 2xw type-c (or faster, thunderbolt) port. Anything much faster than yours requires both as well to stretch its legs. ;)
USB 4 is capable of 40Gbps. Since they are likely to be here in 2022, less than a year from now, they will render this topic obsolete, since every USB 4 cable should be backwards compatible to meet the demands of this drive which standard average USB C cables cannot meet today.

In the meantime, it would appear that your suggestion of a bare minimum 10 Gbps would be the way to go.
Why double the price for a 20 Gbps cable today, when USB 4 will blow it out of the water less than 365 days from now...
What do you think?
For those who don't need it, of course, why get more than you need. For those who do (like me), it is what it is today. That said, faster and faster external drives will come to market (any reason I can't drop a faster rated drive into my caddy?) so a faster interface and cable will be helpful for those who want/need external/portable drives like this.

Thunderbolt4 is already 40 Gbps (so was TB3) and uses Type-C, btw. Both (USB4 and TB4) are going to be intertwined. The problem is that, generally, only premium motherboards have those TB4 ports. Maybe we'll see USB4 ports with next gen Intel and AMD CPUs. But, not sure what that's going to do to cable prices as I believe USB4 is still Type-C and runs at 40 Gbps with 100W of power (like the 20 Gbps cables, but more throughput and, I'd imagine, more costly).

This is a good read: https://www.anandtech.com/show/14526/usb-if-usb4-coming-in-late-2020
Very good.

So I have the first Intel Skylake motherboard and do not plan on upgrading before AMD releases the next generation with full USB 4 support.
Looking at what I have, I notice the following:

First of all, the limit is 10, it does not support 20Gb/s per this screenshot:


Next, I see two USB 3.0 ports and one USB 3.1 port and one USB-C port.

So the screenshot says any cable being connected to USB 3.0 is limited to 5GB/s and should go either to USB 3.1 or USB C to get 10 GB/s and *NOT* USB 3.0.

If the cables went into 3.0 and not 3.1. perhaps that was the reason, and maybe then Womack was right that cables were not to blame?

I can test the ports to find out.
If you were plugged into a 3.0 port (5 Gbps, now called 3.2 Gen1) that would be a limit, yes. Any '3.1' port (now called 3.2 Gen2) is 10 Gbps and optimal for your drive. You may see an increase, but you already determined there is a difference between cables as you saw a performance increase while (I'm assuming) you used the same USB port.
Yes yes.

Here's real life:

Original Cable to USB C:


Original Cable to USB 3.1:


Original Cable to USB 3.0:


and Standard USB-C cable, not original:


So what have we learned? Your USB port MUST BE 3.1, not 3.0.
Your cable cannot be an average USB-C cable you bought on sale, it has to be rated at 10 Gbps, or else your transfer speed may be less than 20% (twenty percent) of what it can be with the original cable (!!)

P. S. Final proof standard USB-C cables cannot be used (sorry Womack):
Here's a cable bought at Walmart, original Samsung USB-C connected to a USB 3.1 port:


Its transfer rate is essentially the same as the average USB-C cables you buy on sale. So you must buy special, more expensive cables, specifically rated to 10 Gbps or more, they will be 500% faster (!!!)

It's about knowing how fast your drive and USB ports are and having the right cable for the job. These suckers are fast... faster than some USB ports, so it's all got to click or it will only be as fast as your slowest part. :thup:


  • 2.png
    91.1 KB · Views: 268
Okay, now that we've established that, there seems to be a 3 foot maximum for these cables.

3 feet is the bare minimum to have easier connection access. So what's considered a good deal on a 3 foot 10GB/s cable?

The original cable is 1 foot, and even 2 feet is too short, the *entire* point here is to have quick permanent access...

$5.99 for 3 feet, will this do:

P.S. They are selling not so expensive cables longer than 3 feet claiming they can do 10 GB/s, what do you think happens when you actually test them, since they are out of specs?
P. S. Final proof standard USB-C cables cannot be used (sorry Womack):
Here's a cable bought at Walmart, original Samsung USB-C connected to a USB 3.1 port:

View attachment 214036

Its transfer rate is essentially the same as the average USB-C cables you buy on sale. So you must buy special, more expensive cables, specifically rated to 10 Gbps or more, they will be 500% faster (!!!)

That's why I said good USB-C cable and I assume they're 3.0+ and not 2.0 with a USB-C connector. And it doesn't mean what brand but how it's made. I used cheap Unitek and Logilink cables from local distribution (available in local electro markets) and both brands were working fine with USB NVMe SSD up to ~1.05GB/s (so max of my X8 or Patriot PXD SSD).

If your SSD stuck at ~30-40MB/s then it can be an issue with the USB driver or the cable can't pass 2.0 standard as every, even old USB 3.0 (A or C) cable should run at 200MB/s+. It happens sometimes.
As ED presented and I add some more:
USB 3.0 = 3.1 Gen1 = USB 3.2 Gen1 = 5Gbps
USB 3.1 Gen1 x2 = 10Gbps
USB 3.1 Gen2 x1 = 10Gbps
USB 3.2 Gen2 x2 = 20Gbps

These cables for smartphones/chargers are usually USB 2.0. So yes, not every standard cable but every cable that meets at least USB 3.1/3.2 specs as it should handle both, Gen 1 and Gen 2 bandwidth. It still doesn't mean you need any special Thunderbolt cable for USB SSD.
Very good. So there is no need for a Thunderbolt cable but we can't use just any cable.

Here are the results of my test. As you can see, this $5.99 cable *can* be used, simply because it says "10Gbps" so it really just comes down to knowing that you cannot use your phone's USB-C cable and you cannot buy just any cable, unless it specifically says that it can do 10 GB/s, like this one:



I have also discovered that these $5 USB extension cables did actually pass through adequate transfer speeds:

But extension cables usually have no ratings like actual USB C cables, so I am guessing it's just a blind shot when it comes to extension cables, but it should be a sure thing for a USB-C cable as long as it actually specifically says 10GBps.
I have also noticed a huge burst of transfer speed initially with these newer cables whereas older ones just do steady transfer from the get-go.
Why do they burst with such high transfer speeds initially?