I use SSDs in an Atomos Ninja V and a Ninja Flame to record high performance video from most of my cameras. When I buy fast SD cards with high speed ratings, like the V90s, it seems like I'm paying about 4X as much for the same performance. There are also some features in the newer model cameras that only work when you hook your camera up to an external monitor/recorder. Stuff like 60 fps, 10 bit, 4:2:2 All-I from some cameras. Most cameras can do a cropped version of 60 fps internally but they tend to write them as 8 bit, 4:2:0 files; and once you've edited the good stuff it's hard to go backwards.
Atomos monitors also enable you to write higher data rate All-I files like Pro Res and DNX when you use their approved drives which bypasses the usual in-camera compression to Long GoP files. Sure, the All-I files are bigger but they are much less complex to edit and they whip through your computers with more ease and elan.
When I bought my first Atomos external monitor/recorder a couple of years ago I also bought two external SSD drives that came pre-loaded in the caddies that fit into a slot on the back of the Atomos recorders and plug into the recording unit with a SATA connection. No wire required.
Both of those units were 256 GB sized drives and they weren't particularly cheap at the time. Now there are a number of units on the market that offer up to 1 TB of fast memory for less money than I paid for each of the 256 units. But that's always the way it goes with any kind of computer memory.
When I bought my Atomos kit it came with three or four plastic caddies one could use to load their own internal-style SSD units into in order to use them with an Atomos. All you had to do was order internal SATA SSD units, put them into the enclosures, then slide them into the SSD slot on the back of your Atomos and you were ready to go. Oh sure, you should probably format the units before use (in the device you'll use them in) but you already know that...
Then, after a long day of shooting video, it dawned on me that I could use the drive I'd just used to capture video to hook to the computer and also edit from. The SSD would offer faster performance than any of the 5400 or 7200 RPM spinning hard drives I'd been using on my desktop and they certainly are a LOT quieter.
All I needed was a SATA to USB-C connecting cable. I started buying WD internal SSD drives in the one terabyte size and putting them in the small, plastic Atomos enclosures then supplying them with $12 StarTach SATA to USB cables and they fire right up. My cost is about $120 per 1 TB drive. I can also disconnect the SATA cable and use each drive, without mods, on the Atomos units.
Yes, I can buy a Samsung 1 TB external in a pretty metal case already ported to USB-C but that doesn't really buy me any more useable performance and then I have to find a source of USB-C to SATA adapters.
So far I've put together three of these Frankenstein "external" SSD drives and they all work without flaws on my iMacPro and on both Ninjas. The WD drives I use are only rated to 540 Mb/s but they are fine handling whatever my recorders are dishing out.
One reason I've stocked up on the SSDs is my desire to shoot my own video work in the latest ProResRaw format. That requires an external drive for for use with all of my ProResRaw capable cameras and I value the larger storage. It's nice not to run out of card space too quickly.
It's kinda weird to work this way for shooters who came up through the photography ranks. You always find yourself thinking that everything should fit inside the camera, not hang on the outside. But if you've come up through the video pathway you're probably used to and comfortable hanging all kinds of crap off your cameras. Why else would they have invented "cages" for video cameras and not for still cameras?
There seems to be a big jump up in prices from 1 TB to 2 TB where SSDs are involved. I have a feeling my desktop will soon be littered with the smaller storage capacity drives but that's okay because I'm pretty good about labeling them.
And actually having to handle a screwdriver and put them in cases makes me feel like one of those D-I-Y Windows users who are always going on about cobbling stuff together on some bench somewhere. Sure, the things they "build" sputter and smoke from time to time, and require weeks or years of troubleshooting but I've heard you can save enough extra money in a couple of years by "building" (assembling?) all your own stuff to pay for a workshop with Lloyd Chambers. In five years you'll have saved up enough to buy a Range Rover.
Of course, the minute Apple introduces their own bespoke designed and branded SSDs I'll buy a case of them and never think twice. Sure, they'll cost way too much but that's what it takes sometimes to make something that both works and is really pretty.
At least I don't have to solder anything.