When it comes to solid-state drives for consumer-oriented systems, the 2.5” form factor is the predominant standard. This is because most notebook designs work with such drives by design, and they easily slide into enthusiast desktops as well.
However, 2.5” drives are too large for sleek notebooks like the Apple MacBook Air. This is where mSATA comes into play: it shrinks storage to the footprint of a Zippo lighter and utilizes a proven interface type, mini PCI Express, for SATA signaling. The SATA-IO already has it standardized, and Intel started trumpeting it earlier this year as well. Now, Intel and Samsung share a common goal: they want to enable a broad adoption of solid-state storage.
Larger 3.5” SSDs only make sense in server scenarios, and 2.5” will definitely remain predominant in the mainstream. The 1.8" form factor is far less prevalent. However, putting system storage onto an mSATA drive facilitates the creation of thinner notebook designs, and even SFF systems can benefit. An mSATA-based storage device could even be mounted on the back-side of a motherboard and not take away any precious PCB space that might be wanted for PCI Express slots or memory sockets (Ed.: Gigabyte has done one better, integrating Intel's SSD 311 on its Z68XP-UD3-iSSD motherboard; neither the Samsung drive we're testing here nor the Intel SSD 310 are great caching solutions due to their MLC-based flash).
Because of space constraints, some mSATA vendors might feel tempted to limit the number of flash memory chips and channels used. This can be a performance issue, but it isn't always the case, depending on the workload in question. Samsung's mSATA drive is a bit slower than the 2.5" model, but the differences aren't very significant for consumer systems. More than anything else, consumer systems require throughput and small latencies, which the drive we tested facilitates using the mSATA form factor. Its write performance is stronger than Intel's SSD 310-series, too.
For us, mSATA is the next logical step to push towards greater integration on highly mobile platforms, because this form factor reduces the physical size of solid-state storage to an absolute minimum. Enabling caching (in the case of Intel's SSD 311) and SSD large enough to serve as boot drive (using this Samsung drive or Intel's SSD 310) doesn't require a big plastic enclosure. It's clearly possible using a compact slot.