It's the Samsung 830 series. Features read speeds around 500MB/s and write speeds around 400MB/s. So pretty darn fast.
I wasn't even betting on a faster SSD, so I'm pretty pleased with these results. My old 128GB SSD BTO on the early 2011 was like 220MB/s read and 200MB/s write or something close to that. More than double? GREAT! So will these things boot in 7 seconds?