Transcend’s new JetDrive adds storage to the new M1 MacBook Pros just by slipping into the SD card slot. It costs $250 for 1TB, compared to $400 to upgrade from 1TB to 2TB at the time of purchase. These two options are far from equivalent. Both have advantages and disadvantages. And if you’re already running out of space, the JetDrive has one big advantage—you don’t need to buy a whole new computer just to add more storage. But it is also slow.  “[I’m] a MacBook Pro user that purchased a 1TB SanDisk Extreme Pro portable SSD for this very reason,” content creator David Woutersen told Lifewire via email. “SD cards like the new JetDrive cards from Transcend may seem like a good idea at first, but if you’re anything more than a casual Mac user, the storage will feel sluggish and slow down your workflow.”

Speed and Reliability

Transcend’s JetDrive has been popular for years, and the new model is more of the same, only with more storage, and designed to fit flush in the SD slot of the new 14- and 16-inch MacBook Pros, with only a tiny protrusion so you can wiggle it out with a fingernail. But it’s still a plain SD card.  The two big downsides of using SD cards for general computer storage are that they are way slower than a built-in or external SSD and also less reliable. I’ve actually tried to use regular SD cards as Time Machine backups and not had much luck, long term.  The internal SSDs of modern Macs are absurdly fast, and even external USB-C and Thunderbolt SSDs are fast enough to stream and edit high-quality video. The 16-inch MacBook Pro, for example, reaches write speeds of between 4400 MB/s and 7398 MB/s, depending on model and disk size, and read speeds that aren’t far behind.  The JetDrive manages just 95/75 MB/s for read/write.  But perhaps that’s the wrong way to think about these expansions. There are several types of personal files on our computers. Those we use a lot, including those that need to be streamed or read fast, and those that we need to keep handy but aren’t in regular use. And the JetDrive can do this while remaining invisible. “Now that I’m holding it, the JetDrive Lite 330 from Transcend feels even smaller than I expected,” tech journalist and reviewer Ed Hardy said on Twitter. 

Backups

I mentioned my trouble using Time Machine with SD cards, but it’s possible to do, especially if you’re only doing it short-term. For instance, you might have a good backup strategy at home or in the office, but that’s all left behind when you travel. Pop a JetDrive into the SD slot before you go, and you can have an on-the-go backup. It won’t help if you lose the computer, but it will help if anything else happens.  Another use is a kind of cold storage for files. Say you’re a musician, and you make lots of amazing songs. Perhaps you’ll want the Logic or Ableton projects to hand, but you don’t need them clogging up the fast internal storage. You could keep them on a JetDrive, and either access them directly or copy them to the main SSD when needed.  The same goes for video files, movies, TV shows for watching in hotels, that kind of thing.  Depending on your tolerance level for untidiness, though, there’s an even better and even cheaper option. Portable SSD drives.  Samsung’s T7 regularly scores well in test results and has the advantage of being tiny and flat. Velcro it to the lid of your MacBook or other laptop, and you can use it on the go. You won’t want to leave it attached all the time because of the battery drain and getting snagged when you put the computer in its case, but a few Velcro dots make this surprisingly convenient. But after all this, perhaps $400 for an extra 1TB of built-in storage isn’t so much worse than the $20 you’ll pay for the far inferior JetDrive.