Q: What is solid state storage?
A: It’s simply storage based on silicon chips rather than things like hard drives, which have moving parts. If you’ve got a digital camera, you’ve already used solid-state storage in the form of plug-in memory cards.
Q: What’s so good about it?
A: It’s physically very compact – think of those tiny memory cards – and it’s exceptionally robust. It can withstand very poor environmental conditions, including all but the most extreme shock and vibration. Unlike hard drives, it has no moving parts that could fail. Finally, power consumption is low. These features make it almost the holy grail of storage media for CCTV.
Q: If it’s so good, why isn’t it being more widely used?
A: Two main reasons – cost and capacity. Solid-state storage devices typically cost around ten to twenty times more per gigabyte of capacity than hard drives. In addition, hard drives with capacities up to around 1 terabyte (1,000 gigabytes) are readily available, whereas the largest solid-state storage devices in common use have capacities of 40 or 80 gigabytes. In short, solid-state storage device capacities are at the level hard disks reached about five years ago.
Q: Does solid-state storage wear out?
A: Although they’re not subject to mechanical wear, present day solid-state devices do have a finite life. Depending on the quality of the device, this can be anywhere from 10,000 to 5 million write cycles. Clearly, there will be an opportunity here for less scrupulous CCTV suppliers to offer ‘cheap’ solid-state storage, but wise buyers and specifiers will stick to products they can rely on from reputable suppliers.
Q: Given those drawbacks, will it really make it into CCTV?
A: It already is! Some systems make provision for solid-state storage to be used as a back-up medium for storing data relating to specific events of interest, and others allow it to be used for transferring data from a CCTV system to, for example, a PC. It’s not yet being used, as far as I know, for the main storage medium in systems but you can be sure it won’t be long before it starts appearing in this role. I expect it to show up first in on-vehicle systems, where its robustness, small size and low power consumption are really important advantages.
