Storage and RAM Flashcards
Storage
This is a permanent store for information that stays even when the system turns off.
HDD
A hard drive that stores memory physically on a spinning disk with a little needle to read and write.
SSD
SSD are basically mass memory chips that have Random Access Memory. Thus they are faster and less prone to physical factors like vibrations or defragmentation. SSD are made of charge traps called charge trap flashes. These traps store a certain amount of electrons to generate a 3 digit binary (000 being a lot of electrons with 111 being no electrons and the levels in between have their own 3-bit designations). When the electron level is set, it can stay for years and has to be forcibly removed to be overwritten. Layers are controlled by bit line selectors while columns are controlled by Control Gate Selectors.
RAM
RAM (Random Access Storage) is volatile memory which means it can store data but it gets erased as soon as the power goes out. These have modules called DIMMs (Dual inline memory modules). For a program to run, it needs to be loaded into RAM first from permanent storage. Lower memory means that some of the data is kept on the slower permanent storage drive.
SDRAM vs DRAM
Any form of dynamic RAM is made up with capacitors that store a charge to dictate the bit number. These leak constantly and need electricity to be refreshed. DRAM (Dynamic RAM) is ram that is not synced to the system clock while SDRAM (Synchronous Dynamic RAM) is synced with the system clock and is way faster.
64 vs 32 bit paths
This refers to the number of bits transferred in one clock cycle.
RAM speed
The speed of SDRAM is measured in hertz (how fast that clock line ticks on and off)
RAM read and write speed (bandwidth)
This is determined on the speed of the RAM as well as the width of the bus in bytes (like 8 byte or smth). When multiplying the two, you get band width (MHz x bytes = mb/s). So if I had 100 MHz and had a 8 byte wide bus my bandwidth would be 800 mb/s.
