Review on Crucial 2TB Portable SSD CT2000X6SSD9 by Richard Simmons

The Crucial X6 4TB drive is not suitable for those who want to fill the drive with large files, e.g. for those who work with video/audio for example. . It uses "dynamic cache", which means that the size of the write cache decreases as the disk fills up. This is an SLC write cache capable of copying files at 800MB/s. The true write speed of the QLC drive is around 80MB/s - slower than most old-school spinning hard drives. When the drive is new and empty, the SLC write cache size is approximately 800GB. So the first 800GB of data you copy to the hard drive is fast. When you run the Blackmagic Disk Speed Test, you accurately measure the speed of the SLC cache. But as soon as you copy 800 GB of data, this SLC cache is almost completely gone. Instead of 800 GB of cache, it quickly drops to 27 GB of fast-write cache. When I heard that the drive has 800GB write cache, I thought it was normal that I can copy 800GB of data, wait a bit of cache. to clean up, then copy another 800GB at the same fast speed. But no, as soon as you only fill the disk to 20%, the write cache drops to 27 GB. (It could fall off more, but I didn't have the patience to keep filling the drive with over 1TB while scanning QLC at 80MB/s!) So the 4TB X6 drive actually has a small 27- GB write cache plus a bonus 775 GB cache that disappears after the first use. The craziest thing is that the dynamic cache never regenerates, after the first use you never get that 800GB of cache back! Even if you delete all the files you've ever copied onto the drive and the drive looks empty in your operating system, the write cache stays at 27GB and never grows to the full 800GB. The only way to get the write cache back to its full original size was to fully secure erase the drive and write zeros across its entire capacity. Since I was planning to use this drive for video editing, I wanted to quickly fill the entire capacity with large file transfers. Not possible with this slow burning QLC disc. For example, the only good use for this drive is for Time Machine backups, where you do a large initial backup and then smaller incremental backups. This is fine for those who never intend to copy files larger than 27GB at a time. The fact that I don't get back the full size of the cache even after deleting all files makes me very suspicious of this drive. I say stay away (I formatted my drive with the APFS file system, which is the current macOS drive format designed for SSDs. When I first connected my drive, I received an error message saying it had fatal errors with an exFAT factory-formatted partition , and this would only be mounted in macOS so it had to be formatted. It's possible the drive behaves a bit differently on other drive formats, I don't know. I personally need it to work with APFS. And I've tried to run the "trimforce" command macOS Mojave, I didn't notice any difference in disk performance.)