Module 6: Storage Devices PDF

MODULE 6 : STORAGE DEVICES _________________________________________ Storage Devices Used to save data in which can be stored short-term or long-term. Can be found inside the computer or outside as an external peripheral Types are: Primary and Secondary Primary Storage: Also known as the ma...

MODULE 6 : STORAGE DEVICES _________________________________________ Storage Devices Used to save data in which can be stored short-term or long-term. Can be found inside the computer or outside as an external peripheral Types are: Primary and Secondary Primary Storage: Also known as the main memory Can store the data temporarily Can be found inside the computer Examples: Random Access Memory (RAM) Read Only Memory (ROM) Cache memory RAM (Random Access Memory) Random Access Memory Main memory Volatile type of memory Types are: Static RAM (SRAM) - data is stored using the six transistor memory cell. Dynamic RAM (DRAM) - made up of a transistor and a capacitor within an integrated circuit, and a data bit is stored in the capacitor. SDRAM, RDRAM, DDR SDRAM SRAM (Static Random Access Memory) SRAM is faster than DRAM Several times more expensive Consume more power Does not require to pause between accesses: cycle time is much shorter It is often used only as a memory Cache DRAM (dynamic random-access memory) Cost-effective It has a short data lifetime Requires to refresh Slower compared to SRAM Less power consumption ROM (Read only memory) Non-volatile type of memory Permanently stores data like to programs used by the computer to perform The chip that is used for BIOS, boot up, accessing devices, etc. Types are: Programmable Read-Only memory (PROM) - blank version of ROM that can be written/modified just once Erasable Programmable Read-only memory (EPROM) - allows for writing and rewriting several times, erasable by ultraviolet light Electrically Erasable Programmable Read-Only Memory (EEPROM) - not only allows rewriting of the program several thousand times CACHE MEMORY Sometimes CPU memory The memory chip that makes retrieving of data from the RAM more efficient Types are: L1 cache L2 cache L3 cache Level 1 caching ○ L1 cache, primary cache, internal cache, or system cache. ○ cache built into the processor that is the fastest and most expensive cache in the computer. ○ stores the most critical files that need to be executed and is the first thing the processor looks when performing an instruction. Level 2 caching ○ Level 2 cache, L2 cache, secondary cache, or external cache, ○ specialized, high-performance computer memory located on the die of the CPU ○ L2 cache was located on the motherboard on earlier computers, although with newer processors it is found on the processor chip. ○ located closer to the CPU, and therefore has lower latency, than the L3 cache. Level 3 caching ○ shared between all CPU cores and is very large in comparison to what an L1 or L2 cache would be on the same chip because it is less expensive, albeit slower. SECONDARY STORAGE Allows you to store your data in long period of time This can be: Magnetic Storage Device Optical Storage Device Solid State Storage Magnetic Storage Device Non-volatile type of memory a storage medium commonly used for large volumes of data Accessing the data can be quite slow Examples are: Hard disk Floppy diskette Cassette tape Optical Storage Device All read and write activities are performed by light Not more costly, light weight, and easy to transport because it is removable device unlike hard drive. All data is saved like as patterns of dots which can be easily read with using of LIGHT. The data is read while bouncing laser beam on the surface of storage medium. Solid State Storage stores data in erasable, rewritable circuitry, rather than on spinning disks or streaming tape Types are: Memory card SSD USB flash drive. Memory Card often used to store photos, videos, or other data in electronic devices. vary in the amount of storage space USB Flash Drive Data stick, pen drive, keychain drive, thumb drive, jump drive Small, portable Often the size of a human thumb, and connects to a computer via a USB port SSD solid state drive no moving parts reduce access time since users don’t have to wait for platter rotation to start up. more expensive than HDDs Cloud Storage The technology that allows us to store the data online and refers it remotely OS provides cloud storage to their users Aside from the developers of OS, there are cloud storage for free: Google Drive Dropbox Common Causes of Data Loss Human Error Viruses & Malware Hard Drive Damage Power Outages Computer Theft Liquid Damage Disasters Software Corruption Hard Drive Formatting Hackers and Insiders