Stefan Mileschin

Micron has announced the first 2.5" SSD which utilizes PCIe interface instead of the more common SATA interface. The 2.5" form factor allows for easy serviceability because the drives can be placed into the front end of servers. Traditional PCIe cards are harder to service and are not hot-swappable, requiring the server to be powered down. Furthermore, using PCIe instead of SATA eliminates the bandwidth bottleneck that SATA produces (maximum of 6Gb/s versus 32Gb/s for PCIe 2.x x8).

The drive is essentially a 2.5" version of Micron's P320h SSD, which Micron announced in June (see our article here). Both use 34nm SLC NAND and are based on the same in-house controller. According to Micron's specifications, the controller is actually one of the fastest to date - providing read speeds of up to 3GB/s and write speeds of up to 2GB/s (yes, with a big B, i.e. bytes). Random 4KB read performance maxes out at 750K IOPS, while random read tops out at 341K IOPS (700GB version).

However, keep in mind that the controller features 32 channels. 2.5" SSDs typically utilize 16 NAND packages, which means only half of the available channels would be in use with Micron's controller. Micron couldn't provide us with any detailed specifications or performance figures yet as this announcement was for promoting the new interface, not the actual drive, so we don't know how much the performance differs from the FHHL sized PCIe card. The capacities are a bit smaller at 175GB and 350GB and at least random write performance should be slightly lower than what the FHHL card offers, but it's certain that this will be one of the fastest (if not the fastest) 2.5" SSDs.

Micron is currently sampling interested customers and an actual product announcement is going to follow later this year with more specific performance details. No pricing has been revealed, but Micron hinted that the price of the FHHL card would be over $16 per GB, which works out to be $2800 for 175GB and $5600 for 350GB if the 2.5" version is priced similarly.

http://www.anandtech.com/show/5637/m...or-enterprises