Specifications, Availability and Pricing
The Seagate Cheetah 15K.7 is available in two interfaces, Fiber Channel and SAS 2.0. For this review we are going to focus on the SAS version. The latest Cheetah is available in 300, 450 and 600GB capacity sizes and all of the drives use 16MB of cache. These drives use the traditional 3.5 inch form factor; Seagate does make a 15,000 RPM 2.5 inch drive but it is in the Savvio Series and is now in its second generation.
The purpose of 15,000 RPM hard drives is to reduce access latency, the by product is increased I/O performance. Database and web servers are two areas that see significant performance increases with faster spindle speeds. If you are not familiar with spindle speeds, it is the number of revolutions per minute (RPM) the platters pass a fixed point of reference. Typical speeds include 5,400, 7,200, 10,000 and the highest available 15,000 RPMs. In recent years a few others have made an appearance; we are starting to see some dynamic speeds, but for the most part hard drives are categorized by these four fixed points.
Seagate claims the 15K.7 Cheetah has an ultra low 2.0 ms access time on average. This is possible only with a very high platter speed or solid state products. While it is true that solid state drives measure access time to a hundredth of a second, platter based drives still have several positive features that make them more viable in most usage scenarios.
The 15K.7 has the highest Mean Time Between Failures (MTBF) of any drive on the market and is rated at 1,600,000 hours. You may think that this kind of reliability would make the drive perfect for consumer use and with several desktop motherboards starting to include SAS data ports, it is an option. The cost is a little prohibitive, the 300 GB drive can be found online for around 300 Dollars, the 450GB for 445 and the 600GB that we are reviewing today for 676 USD, all pricing taken from Google's Shopping Service.