We're talking about two types of memory. Flash memory is low-cost and it retains data when power is removed (nonvolatile), but its performance is also slow. Conventional RAM -- the "main memory" of your PC or server -- is much faster, but it's a bit more expensive and requires constant power. These two memory types are very different, but vendors may refer to both as "solid-state memory," so consider what you're buying.
More resources on RAM and flash memory
Memory has a huge part to play in future drive designs as both a power-saving and performance-boosting tactic. For example, we'll likely see laptops with hybrid drives offering flash memory so that the laptop can boot without actually spinning the hard drive. We're also seeing high-performance disk drives with DDR RAM. Texas Memory Systems can package 1 terabyte (TB) of solid-state memory in a 24U cabinet. Flash and RAM memory prices continue to fall, so hybrid and solid-state drives will become more economical into the future.
Go back to the beginning of the Disk Hardware FAQ Guide.