Page 35 - 4130

faster speed than RAM and is fully capable of processing more
information than the quantity the main memory can transmit to it at
any one time. In order to speed up the performance of computers,
manufacturers create smaller units of the costly faster memory to
supplement less expensive, but larger amounts of RAM. The
structure of memory in a computer, from fastest to slowest is cache,
RAM, virtual memory and hard disk drive.
Cache - The power and speed of modern central processing
units necessitate memory that can feed it data at the speed it operates.
Otherwise, the CPU is idle when it can be working, thus speeding up
the overall computing process. Caches are memory circuits that work
with RAM by accelerating the task of moving data to the CPU. The
L2 cache is integrated on the motherboard right next to the processor.
The L2 cache stores the most recent data used by the CPU. When the
processor needs that data again, it will first look in the L2 cache. If
it's there, the time required to access the information is up to two
times faster than going to RAM. The fastest memory element is the
L1 cache. It is integrated into the CPU and operates at the same
speed as the processor.
RAM -Random access memory (RAM) is the main memory
for the computer. Data is transmitted between the central processing
unit and RAM. It's referred to as random because any information it
contains can be retrieved directly without the need to proceed to it in
a sequential manner. RAM is volatile, which means that all the data
it holds is lost when power is turned off to the system. Even as RAM
has grown in speed and capacity over the years, it still does not have
the speed that is necessary to keep up with the amount of data the
CPU is capable of processing at any one time
Virtual Memory - Before virtual memory, if you had too
many programs opened at once on your computer you would receive
a message informing you that the computer is out of memory. You
would have to close an application, or two, before you could load the
program you want. Now, the system automatically searches out
compartments of data on main memory that the CPU has not

33