Solid State Hard Drive

Solid state hard drives known as SSD have been around for over 30 years. They haven’t been commonly used by manufactures, until recently when they have been recreated and used in portable devices such as Ipad and iPhones. This has to do with the expense of the SSD’s. Prior to the SSD manufactures have been using the Hard Disk Drive (HDD), which is designed completely different. HDD,s use a rotating disk which is accessed by a mechanical actuator, which SSD’s use nonvolatile memory. This makes for less moving parts and makes the SSD less fragile. SSD’s are used in smart phones and digital cameras. We know them as secure digital cards (SD cards) and flash drives; these are less complex versions of the SSD. The difference of a SSD and the version that is used in our mobile devices is the performance requirements. The memory needed for a digital camera is less demanding than what a multi core possessor laptop or a data server would need. More complex versions of the drives are made up of 3 blocks storage media, a controller for managing the media, and a host interface for accessing the media. When is come to comparing the SSD and HDD, they both are made to boot up our systems store applications, and our personal files. Booting up a SSD it will boot in seconds while a HDD takes longer because it has to spin up the disk to operating speed. HDD’s are also slow when it comes to accessing your files because it has to spin and practically find the file that you are looking for, and they tend to get fragmented after time. Fragmentation is when files get scattered across the disk platter and the read/write head takes longer to find larger files. While on a SSD no matter where or the size of the file is on the chip it does not take time to find the files. SSD’s are also a lot more durable. HDD’s have the moving parts and when they aren’t powered on the read/write head is sitting still on the disk platter. Any type of drop or impact will cause the head to misplace itself on the platter, which can cause your files to become inaccessible. HDD’s also emit noise even the more advanced versions still make a little noise from the spinning of the disk platter. A downfall of the SSD is that the memory cells have a limit of how many times it can be rewritten on, but they last a very long time when they are being used for normal activities. In the near future there are new types of memory that will become standard in our devices such as RRAM Resistive Random Access Memory. This type of memory will be similar to a flash driver where it will not need a constant power supply to store data. RRAM stores bits using resistance which allows more bits to be stored in a given area. The prototype RRAM chips are the size of a post stamp and can store a whole terabyte. The first use of the chips will most likely be used in devices such as mobile phones and other portable devices.
After doing my research on Solid state drives and Hard Disk Drives I have learned a lot. One thing I learned is how the data stored on a drive is accessed by the computer or device. The NAND media stores the data in a no power state, a charge is then sent to the chip. When saving data to the drive electrons are added to the chip and when erasing data electrons are removed using a high pulse of voltage. I also learned how the information in the SSD is managed, there equipped with a Controller. The controller is an embedded stand-alone system on the SSD which is for processing and firmware for managing all aspects of the SSD. This research had given me a better understanding in the way the SSD’s, HDD’s, flash drives, and the future of computer memory such as RRAM work. This will be useful to me and others when we began to trouble shoot devices and computers that use these types of memory.

APA(American Psychological Assoc.)
References
Cornwell, M. (2012). Anatomy of a Solid-State Drive. Communications of The ACM, 55(12), 59-63. doi:10.1145/2380656.2380672
APA
(American Psychological Assoc.)
References
Domingo, J. S. (2012). SSD vs HDD: What's the Difference?. PC Magazine, 1.

Super Dense Computer Memory
By Kevin Bullis on July 23, 2014