Man Vs Machine (pg
2 of 3)
brain - So far, we have never heard of anybody's brain
being "overloaded" because it has ran out of memory. (So
it seems as if, the human brain has no limit as to how much memory
it can hold. That may not be true)
Our best possible guess of the average
human brain's capacity would by calculating using the number of
synapses connecting the neurons in the human brain. Because each
of the synapses have different molecular states, we estimate each
of them to be capable holding one megabyte worth of memory. Since
the brain has 100-trillion-synapses, we can safely say that the
average brain can hold about 100 million megabytes of memory !!!
Remember what we said about the Megabyte/MIPS
ratio of a computer ? By calculation, scientists discovered that
the brain's memory/MIPS ratio matches that of modern computers.
The megabyte/MIPS ratio seems to hold for nervous systems too!
However, we all know that the memory
of the brain is not absolute. It does not have set files or directories
that can be deleted, copied or archived like those of a computer.
For example, a particular person who thought he had memorized a
telephone number for good suddenly realizes he can't recall the
number. But some half-a-day later, he may suddenly recall the number
again.) It is a strange phenomenal that we still can't really explain.
A simple thoery is that the brain treats parts and peices of these
ignored memories like a unactive "archives" sections until
they are required. Memory spans of parts of the brain seem to depend
on how often they are used. Even so, there is no such thing as deletion
of data in a brain.
- Computers have more than one form of memory. We can generally
classify them into primary and secondary memory. Primary memory
is used as a form of temporary memory for calculation processes
and storage of temporary values that need rapid access or updating,
the contents of the primary memory disappear when the power is turned
off. Primary memory is important when executing programs, bigger
programs require more primary memory. ( RAM(random access memory),
Caches & buffers are just a few examples of primary memory)
Secondary memory often comes in the
form of hard disks, removable disk drives and tape drives. Secondary
memory is used for the storage of most of a system's data, programs
and all other permanent data that should stay there even when the
power is turned off. As a computer is fed with bigger, smarter programs
and more data, it would naturally need more secondary memory to
The latest, greatest super computers
(as of 1998) have a million megabytes of memory. Today's latest
model of hard disk drives on the personal computer market (in early
2000) can hold about 40,000 megabytes
(40 gigabytes) of memory.