Hardware Reference
In-Depth Information
operate. However, water cooling can be expensive to set up, and a leak in the water cooling
subsystem can ruin other components.
Can I Upgrade My Processor?
The relationship between the processor and the motherboard is very close, because they
must work together seamlessly. Not only must the processor be physically compatible
with the motherboard's processor socket, but the motherboard must also be aware of
the processor's instruction set and the speed at which it can accept data. As a result,
most motherboards support only a few processors, so upgrading to a signifi cantly better
processor without replacing the motherboard usually isn't possible.
Memory
Memory
, generically speaking, is data storage that uses on/off states on a chip to record
patterns of binary data (that is, data that consists of only 1s and 0s). Inside a memory chip
is a grid of on/off switches. An on value represents 1, and an off value represents 0.
Memory can be either static or dynamic.
Static memory
(a.k.a.
nonvolatile memory
)
doesn't require refreshing to maintain its contents.
Dynamic memory
(aka
volatile memory
)
has to be constantly powered on to retain its contents.
Broadly speaking, all memory can be divided into one of two types: ROM and RAM.
Read-only memory (ROM)
chips store data
very
permanently; you can't make changes to
their content at all. (It takes a special ROM-writing machine to write one.) This type of
memory is always static. The basic startup instructions (BIOS) stored on your motherboard
are typically stored on a ROM chip. So is the programming on simple electronic devices
that will never need to be user-updated, like the computer on an exercise treadmill that
stores various fi tness programs. The main advantage of ROM is its reliability. It can never
be accidentally changed or deleted. The disadvantages of ROM are that it's slow compared
to RAM, and that you can't ever update it; you have to pull the chip out of the system and
replace it. Because of these drawbacks, ROM isn't used as a PC's primary memory source;
a PC has only a small amount of ROM.
Random access memory (RAM)
can be written and rewritten on the device in which
it's installed. It's called
random access
because the data is stored in whatever locations are
available in it, and reading data back from it doesn't require that the data be in a certain
storage location.
RAM can be either static or dynamic.
Static RAM (SRAM),
also called fl ash RAM, is
the type you use when you store fi les on a USB fl ash drive. Static RAM is nonvolatile; you
can disconnect a fl ash RAM device and carry it with you, and the next time you connect
it to a computer, the data will still be there. Most of the memory on a PC's motherboard is
