RAM Overview• RAM stands for Random Access Memory. It gets the word "random" because information can be accessed in non-sequential order. Though the data itself is stored together, it could be anywhere in the "container" or amount of RAM available. RAM is measured in "bits", and 8 bits equals 1 byte. A kilobyte equals 1024 bits, and a megabyte equals 1024 kilobytes.
Two Main Form of RAM DRAM SRAM (Dynamic(Static Ram) Ram)
SRAM (Static Ram)• Static RAM is a type of RAM that holds its data without external refresh, for as long as power is supplied to the circuit. This is contrasted to dynamic RAM (DRAM), which must be refreshed many times per second in order to hold its data contents. SRAMs are used for specific applications within the PC, where their strengths outweigh their weaknesses compared to DRAM:
• Simplicity: SRAMs dont require external refresh circuitry or other work in order for them to keep their data intact.• Speed: SRAM is faster than DRAM.• Compared to DRAM, SRAM is more power- efficient when idle.• SRAM is several times more expensive than DRAM.
DRAM (Dynamic Ram)• Dynamic RAM is the standard computer memory of the vast majority of modern desktop computers. It is a volatile memory that needs to be refreshed with voltage regularly, otherwise it loses the information stored on it. Dynamic RAM is also referred to as DRAM. Volatile means that it loses the information stored on it as soon as power is withdrawn.
• Dynamic RAM is referred to by its size and speed. For example, the packaging or description of the memory module might list 1066 Mhz 1 Gb DRAM. The 1066 Mhz is the speed at which a computer can read and write to the memory, and the higher number the better. The 1 Gb is the usable space on the chip; in this example, the chip can store 1 gigabyte of information on it while it has power. There are several different types of DRAM.• Example of DRAM is DIMM, SO-DIMM and DDR Memory Sticks.
Types of RAM Memory Module•1• Computer memory has a big effect on system performance. Pictured above is SIMM memory, or single in-line memory module, which is a type of RAM memory module.
•2• DIMM, or dual in-line memory module, has a 64-bit path to memory chips, whereas the SIMM has only a 32-bit.
•3• SO-DIMM, or small outline dual in-line memory module, is made with integrated circuits and is about half the size of DIMM modules