A high-speed cable that can be used with many devices.

While many people think that USB-C is a relatively new method of connectivity the truth is that it’s been available as a connector since 2014. For the past six years, it’s been slowly phased in as the data and charging connector of choice for smartphone designers, computer manufacturers, and accessory makers. USB-C was actually developed alongside the USB 3.1 specification and until last year, it was only capable of operating at speeds of 10 and 20 GB/s. In 2019, however, USB4 was released as the first USB transfer protocol that is available through USB-C. Now, a USB-C cable enabled with USB4 can transfer at speeds up to 40 GB/s. ACCELL Corporation released a brand new USB4 capable cable that is an all-in-one connector for data, video, and power. 


Up to 40Gbps operation over 40Gbps-certified cables
Supports up to single 8K resolution or dual 4K displays at 60Hz
Two-lane operation using existing USB Type-C® cables
Dynamic bandwidth data sharing with double the bandwidth to extend USB Type-C® performance
USB4™ hosts can optimally scale allocations for display data flow
Backward compatibility with USB 3.2, USB 2.0, and Thunderbolt 3
Length: 2.6 ft / 0.8 m


The cable comes in a simple plastic zipper pouch. The front of the bag has a sticker on the front that includes all the details of the cable. The cable is wound up tightly as a loop. It is tied off at each end with a simple twist tie. As I was examining the cable I noticed that near one of the ends the cable wrap was crimped. I also noticed that there was a tear in the bag so it’s possible that happened in shipping, but because this is a cable, it was concerning to me. Fortunately, the cable wrapping wasn’t breached and I couldn’t see any of the actual wiring on the inside. 

As far as cable quality goes, it feels exceptionally thick. The cable is still flexible, but it’s stiff at first. Because it’s only 2.6ft long, you are limited as to what you can use it for. As a first test, I decided to plug my iPad Pro in to charge using this new USB-C cable. It connected right away and started charging. 

Next, I decided to test the cable out by connecting and running speed tests on a couple of external hard drives. Both hard drives are made by G-Technology and are designed for mobile use. The G-Drive Mobile Pro holds an SSD in its case and connects using Thunderbolt 3. The G-Drive Mobile USB-C has a standard 2.5-inch hard drive inside its case and connects using USB-C (USB 3.1, Gen 1). With those specs, the G-Drive Mobile USB-C should be able to transfer up to 5 GB/s. The G-Drive Mobile Pro should be able to transfer at speeds up to 40 GB/s when connected using a Thunderbolt 3 cable. Now, I want to point something out. Thunderbolt 3 and USB-C both use a Type-C connector, but have different imprints inside. 

In order to test out the USB4 cable, I used it to connect both drives to my MacBook Pro. I checked the system profile of the hard drive while it was connected using the USB4 cable and I ran a speed test (Blackmagic Speed Test) to check the cable’s performance. The control of this test was that I also ran the same tests with the intended cables for each drive. The table below shows the results. The USB4 cable was actually a suitable replacement cable for both hard drives. I was actually surprised that the Thunderbolt 3 hard drive even connected with it, but sure enough. It did. 

ACCELL USB4 CableThunderbolt 3 CableUSB-C Cable
G-Drive Mobile Pro
(Thunderbolt 3)
1323.9 MB/s WRITE
1204.5 MB/s READ
1363.4 MB/s WRITE
1329.1 MB/s READ
G-Drive Mobile
120.2 MB/s WRITE
131.0 MB/s READ
119.3 MB/s WRITE
130.4 MB/s READ

It’s important to note that even though a cable may be capable of certain speeds, the connected device may not be. So, you will notice that with the speed test above the speeds are nearly identical. This is likely because the device will regulate a top speed. The most interesting observation I made during these tests was actually the fact that the G-Drive Mobile Pro drive registered different data transfer speeds in the system profile information. When the USB4 cable was connected, the speed was listed as “up to 20 GB/s” and when it was connected with a Thunderbolt 3 cable, the speed was listed as “up to 40 GB/s”. I believe the variance in the speed is because the USB4 cable is longer and therefore – passive. According to StarTech.com, active cables can achieve the full 40 GB/s while passive cables can only reach speeds up to 20 GB/s. The difference between the two cables – other than speeds – is their length. The active cables are 0.5m long. While the USB4 cable is only 0.8m in length, it’s still longer than the Thunderbolt 3 cable I used. 


The ACCELL USB4 cable seems to work very well. While I didn’t have any USB4 devices available for testing, the cable did prove to be a better asset than a standard USB-C cable. One thing I’ll note is that a USB4 cable can be very handy to carry around if you are using USB-C and Thunderbolt 3 devices so that you don’t have to carry around multiple cables. I don’t know for sure if this will work with all Thunderbolt 3 devices, but so far it has for me. While we don’t currently have an M1 MacBook Pro in-house once we do, this review will be updated with additional information. 

For more details, visit ACCELL, Facebook, and Twitter.