CalDigit T4 Thunderbolt 3: more features, slightly faster

The T4 Thunderbolt 3 is CalDigit’s newest RAID storage solution. Except for the Thunderbolt 3 interface, the new T4 comes with a DisplayPort that allows you to connect to any monitor with a resolution of up to 4K@60Hz. It also has the ability to charge an attached laptop through the Thunderbolt 3 port with up to 85W of power.

The new T4 is – again – an SSD or HDD based hybrid RAID solution, factory configured for macOS. If you opt for hard disks inside, you can now have up to 32GB of storage space. My test unit was an 8TB model that was factory set to RAID 5. I decided to change the RAID mode to RAID 0. I ran my tests in April 2018, and that was a bit too early for CalDigit to be fully ready with its RAID management extension.

To configure RAID modes, CalDigit’s menu extension had to be updated for the new features of the T4 and it appears that the version of April 19, 2018 wasn’t entirely bug free. It formatted another one of my mounted volumes instead of the T4. Luckily, CalDigit was quick enough to release an update. Still, backing up before installing software that tampers with hardware is always best, as I learned the hard way.

The new T4’s performance hasn’t changed too much, despite the dual Thunderbolt 3 interface. That’s partly due to the fact that you can’t get more out of a SATA hard disk than the highest speed of the disk itself and the interface. Some 700MB/sec in RAID 0 is quite good and I was able to squeeze that out of the new T4.

If you install SSDs instead of the hard disk drives my test unit came with, performance may improve somewhat more, but it will, of course, never achieve the speed you will get from an M.2 connected SSD RAID. Perhaps CalDigit will release such a M.2 SSD RAID later this year? It sure would be incredible news.

The DisplayPort on the back of the device drove a 5K monitor without problems and the MacBook that was hooked up to it also charged fine with the unit in standby mode.

In short, the CalDigit T4 Thunderbolt 3 performs very well, but with SSDs inside, it is held back by the SATA interface that is starting to show its age. Still, you can edit a 4K movie with ease using a T4 in RAID 0 as your production unit.