RDRAM Computer Memory Upgrade Chips
If your computer's CPU had to constantly access the hard drive to retrieve every piece of data it needs, it would operate very slowly. When the information is kept in memory, the CPU can access it much more quickly. Most forms of memory are intended to store data temporarily. Virtual memory is a common part of most operating systems on desktop computers. It has become so common because it provides a big benefit for users at a very low cost.
RAM is a type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers. Dynamic RAM needs to be refreshed thousands of times per second. Static RAM does not need to be refreshed, which makes it faster; but it is also more expensive than dynamic RAM. Both types of RAM are volatile, meaning that they lose their contents when you turn the power off.
The term SIMM stands for Single In-Line Memory Module.. With SIMMs, memory chips are soldered onto a modular printed circuit board (PCB), which inserts into a socket on the system board. It's been proven that adding more memory to a computer system increases its performance.
If there isn't enough room in memory for all the information the CPU needs, the computer has to set up what's known as a virtual memory file. In so doing, the CPU reserves space on the hard disk to simulate additional RAM. This process, referred to as "swapping", slows the system down. In an average computer, it takes the CPU approximately 200 ns (nanoseconds) to access RAM compared to 12,000,000ns to access the hard drive. This would be equivalent to what's normally a 3 1/2 minute task taking 4 1/2 months to complete! RIMM is the trademarked name for a Direct Rambus memory module. RIMMs look similar to DIMMs, but have a different pin count. RIMMs transfer data in 16-bit chunks.
EDO DRAM is most likely found on computers that are six years old or older. When you work with an application on your computer, the program is loaded into "main memory". Of course there are several other kinds of memory besides main memory. For example, there is "cache" and "flash BIOS" memory. A computer consists primarily of memory. Even the CPU has a type of memory referred to as "registers".
SDRAM is available in a 168-pin dual inline memory module (DIMM) package. It comes in two speeds: 100 MHz (PC100) and 133 MHz (PC133) and two voltages: 3.3 volt and 5 volts. Some SDRAM "sticks" contain a bit of extra circuitry called "error checking and correction" (ECC) that stores extra bits along with the data. These extra bits are used by the CPU to verify the validity of the data and correct any errors that it finds. RAM is the best known form of computer memory.
RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell.
A CPU's bit size tells you how many bytes of information it can access from RAM at the same time. For example, a 16-bit CPU can process 2 bytes at a time (1 byte = 8 bits, so 16 bits = 2 bytes), and a 64-bit CPU can process 8 bytes at a time.
Memory speeds are written in different formats depending on the type of memory technology your computer uses. FPM and EDO speeds are written in nanoseconds (ns). SDRAM and DDR speeds are written in megahertz (MHz) or with a "PC" rating.
SDRAM is rated at the straight clock rating of the memory. SDRAM can be found in speeds ranging from 66 megahertz up to 133 megahertz. They are sometimes referred to by the speed rating preceded by PC. Thus PC133 SDRAM runs at a 133 megahertz speed.
SDRAM is available in three clock speeds: 66, 100, and 133MHz.. Motherboards are designed to support specific types of RAM. You should always check which types of memory can be fitted before supplying or installing upgrades.
DDR 1 | DDR 2 | DDR 3 | Flash 1 | Flash 2 | USB 1 | USB 2 | USB 3 | SDRAM 1 | SDRAM 2 | RDRAM 1 | | RDRAM 2 | MISC |
