• Solid-state disks are RAM that is presented as disk drives: – Lower power consumption compared to hard disks – Cost generally limits applications
• Where will SSDs provide the most performance improvement? – Low latency is the primary advantage of SSDs – Reduced “seek time” for reads and writes – Environments that require highly random I/Os will benefit
Solid-state disks are collections of RAM organized to look like a hard disk to the system. They are several dozen times faster in seeks and reads than a conventional hard disk, but they are also much more expensive than hard disks. The cost of solid-state disks has generally limited their use to specialized applications.
Typically cache is increased instead of using solid-state disks. However, there are times when it makes sense to put all the active data on a solid-state disk. If an application sustains a high volume of I/O that exceeds the ability of the cache to destage to disk, the cache will eventually fill. It won't matter how much cache you have-- more cache will just mean a few more seconds or minutes before the cache is all dirty and the application must start writing directly to disk.