Seagate Cheetah 15K.5, 3.5” SAS at 15,000 RPM
The Cheetah has been Seagate’s high performance enterprise hard drive family for some time. These are 3.5” hard drives running at 15,000 RPM, and they are available at 300 GB, 146 GB and 73 GB capacity points. All drives come with 16 MB of cache memory.
One issue to consider is power consumption and drive temperature, which is much more of an issue here than with 7,200 RPM desktop hard drives. All 15,000 RPM drives require active cooling, and they are also noisy when compared to desktop models. Flash SSDs, however, require almost zero cooling, consume only a few watts as opposed to 5-15 W and make absolutely no noise.
Impressive Performance
The Cheetah 15K.5 delivered up to 128 MB/s maximum throughput, which makes it the fastest mechanical hard drive we’ve ever seen in our test labs. The minimum transfer performance of 61 MB/s also is an excellent result, although the average rate of 107 MB/s is more impressive. Clearly, this drive delivers up to 40% higher transfer rates than the Savvio 10K.2. We also found the 5.9 ms average access time to be best of class. Remember that 3.5” desktop hard drives at 7,200 RPM are at 12-15 ms, taking twice as long, on average, for access.
Beating the Flash SSDs in Sequential Writes
When looking at write throughput, the Cheetah 15K.5 delivers higher performance than the 104 MB/s we’ve seen with the MemoRight flash SSDs, unless you use the entire capacity and force the hard drives to use the inner areas of the rotating platters, which typically are the slowest. This result is reflected in the PCMark 05 File Write benchmark, which shows 20% better performance for the Cheetah 15K.5.
Let’s see what the Cheetah 15K.5 can do in a RAID 0 configuration with eight hard drives.
