The main differences between the two drives are their spindle speeds and seek time. The 15K.7 is claimed to be the fastest 3.5-inch enterprise drive at 15,000rpm, rated at 15,000rpm with a seek time of 3.4ms, while the NS.2 spins at 10,000rpm and has seek time of 3.8ms. Other than that, both drives will be available in capacities of 300GB, 450GB and 600GB and will support data transfer rates of either 6Gbit/s on a SAS-2.0 interface or 4Gbit/s on Fibre Channel.
The Cheetah NS.2 is reportedly available now and the 15K.7 drive is currently undergoing OEM qualifications and will start shipping to channel partners next quarter. However, pricing details are yet to be announced.