To solve performance problems, many data centers are turning to the solid state disk (SSD), but there is a question about how to best leverage this high-speed device in new systems often referred to as hybrid SSD storage systems.

The emerging implementation method is to use caching technologies to automatically move the most active subset of data to the more premium storage tier, and combine that with near-line SAS hard disks to storage the least-active, least-performance-sensitive data. In theory, this should give the perfect balance of price and performance. But there is a performance gap to be aware of.

The concern with these systems is that in an effort to hit an ideal price-performance number, there is risk of a significant potential performance drop because of a cache miss. The performance delta between the two tiers — SSD vs. near-line hard drives — is large on a per-drive basis.
Network Computing