There are hard disk drives that deliver stability for your data along with lots of space, but with poor read and write performance. There are solid state drives that deliver blazingly fast read and write performance compared to hard disk drives at the cost of a shorter life span and higher chance of corrupt data. And then there are solid state hybrid drives that offer the best of both worlds, almost.
Seagate, who has been working with IBM, has announced two new 2.5" SSHDs, called the IBM G2HS and IBM G2SS, intended for enterprise servers. The drives are both 10,000 RPM SAS drives with 600 GB of storage, 16 GB of NAND flash, and 128 MB of cache on-board. The added NAND flash, high amount of cache, and intelligent algorithms are what will allow the SSHDs to reach Seagate's target of a 100% improvement in I/O over regular 10,000 RPM drives.
The 600 GB of magnetic storage will be storing all data written along with a primary copy of all the cached data; the 128 MB of DRAM will be used to buffer all reads and cache all writes; and the 16 GB of eMLC NAND is used as a read cache for all active data, and as a non-volatile cache for writes cached in the DRAM. This will allow for much better read and write performance, while minimizing the risk of corruption of the data.
IBM and Seagate have been testing these drives against regular 300 GB 10,000 RPM hard drives, and the results are quite impressive. The SSHDs manages IOPS over two times better than the regular drives, and at low latency (< 5 ms) the SSHDs are 15 times better. This is not all though. The blog post ends with these words: "Even faster enterprise SSHDs ... will be available later this year…stay tuned"