The drive is brand new and has the latest firmware installed. Let’s start our tests. The CrystalDiskMark software also offers a good indication of the drive's possible performance. The drive seems to introduce around 150MB/sec reading/writing speed with sequential files, while random 4K speed isn't high, something that was expected from a 5400rpm HDD.

The ATTO Disk benchmark gives us more details with different file sizes and something strange happens with low writing speeds at an 8MB file size:

while the ATTO Disk Benchmark didn't show high writing performance as well.

Using life real testing, writing performance wasn't very stable with up to 120.9MB/sec when writing a large single file, which means at some point performance drops from 150MB/sec to 120MB/sec:

Working temperatures are also great, no issue here with a max around 35 Celsius under constant load.

- Conclusion

The Toshiba Canvio Flex series is a nice solution for users who wish for external-portable HDDs with low weight, great price, and good performance. The low weight and dimensions of this product make it truly portable and easy to carry around. The retail price for the 4TB is slightly higher (114 Euro) than the competition, so we are expecting good performance. At the retail package, two cables are provided, either with a normal TypeA or TypeC connection for a truly universal product for PC/MAC users.

The Toshiba Canvio Flex 4TB benchmarks were good in most cases, provided that the testing file was higher than 4K/8K sized. The used 5400rpm speed HDD offers a low noise level and good working temperatures even at full load. The product comes with 3 years of warranty which is also nice to have. We hope in the future Toshiba will move away from the MicroB to TypeA/C idea and offer a direct TypeC connector for all their external solutions to carry one cable for all your portable devices. Lastly, the device due to its exFAT file system is compatible with Windows, MAC and even Android devices so don't worry, you have to use it on all devices you might have around, great product with a great price as well, and good work from Toshiba.