Bite-sized mSATA SSDs are perfect for notebooks and small-form-factor systems like Intel's NUC. Their storage capacities used to be somewhat limited, but not anymore. Samsung has rolled out a family of mini 840 EVO SSDs that includes models up to 1TB.
This Samsung blog post announced the new additions, and the performance ratings provided for the flagship model match those of its desktop counterpart: 540/520MB/s for sequential reads/writes and 98/90k IOps for random I/O. We've actually been testing the 2.5" 840 EVO 1TB for an upcoming article. That drive is very impressive overall, so the mSATA version promises to be one of the fastest SSDs out there.
The mSATA version of the EVO supports TCG/Opal and IEEE 1667 encryption standards out of the box. Similar functionality is now available for the desktop drive via the latest EXT0BB6Q firmware update. Interestingly, that update includes a tweaked algorithm for the TurboWrite flash cache. (The EVO combines TLC main storage with an SLC write cache.) The mSATA drive presumably has the same optimization baked into its initial firmware.
The 840 EVO also supports RAPID mode, a DRAM-based caching scheme that works through Samsung's SSD Magician utility software. Version 4.3 of that app brings RAPID support to the 840 Pro, though I wouldn't recommend enabling the feature. RAPID mode delivered mixed results when we tested it on the 840 EVO a few months ago. We didn't see an improvement in application load times, and using the scheme to cache writes could be risky. Still, it's nice to see Samsung deliver on its promise to port RAPID mode to the older 840 Pro.