Computer Memory

Advantages of pen drives are that they are resistant to scratches and dust. Some pen drives are water proof and can function even after being submerged in water. Their solid-state design means they often survive casual abuse. They are ideal for transporting personal data or work files from one location to another. The near ubiquity of USB support on modern computers makes it work everywhere. Pen drives have immense storage capacity and even inexpensive ones will hold lots of data. Top of the line pen drives have 64 GB storage. Power consumption of a typical flash drive is very low. Pen drives have no moving parts meaning that most modern operating systems can read and write to flash drives without any additional device turners. Pen drives are much more tolerant of abuse than mechanical drives.

Disadvantages are that they can sustain limited number of write and erase cycles before failure. Mid-range pen drives under normal conditions will support several hundred thousand cycles, although write operations will gradually slow as the device ages. Most USB pen drives do not include a write-protect mechanism. Write-protection makes a device suitable for repairing virus contaminated host computers without risk of infecting the USB flash drive itself. A drawback to the small size is that they are easily misplaced or lost. This is a particular problem if the data they contain are sensitive. It is for this reason that pen drives are now coming attached to key chains, necklaces and lanyards. They have limited capacity when compared to disk drives even in 2.5inch form factors. They get damaged or data is corrupted by severe physical impacts. Improperly wired USB ports can also destroy the circuitry of pen drives. Pendrives are costly.

No. Hertz, megahertz, gigahertz, etc, are all measures of frequency. This is used to quantify a rate of change, such as the speed of the processor's clock signal. If anything changes at a rate of N Hertz, the observed item changes its state from one state to another N times per second. For example, a 10 MHz clock crystal oscillates between its two states 10 million times per second.

RAM (memory) is typically measured in bytes, kilobytes, megabytes, or gigabytes, or in multiples of bits (kilobits, megabits, etc). RAM is implemented as an electronic device also is characterized by a number of frequencies, such as the maximum speed of change for certain input signals, or the maximum rate of change of certain output signals of a RAM chip. In that sense, a frequency figure can very well be used to describe certain characteristics of RAM, however, the principal characteristic is its storage capacity in bits or bytes.

Storage (harddrive) is also quantified in bytes, megabytes, gigabytes, terabytes.