space/time

The following units of measure are used to define digital capacities and speeds. For measurements of a meter, see metric system. See binary values, NIST binary and long scale.

************************************** S P A C E **************************************                      10 to theBits or Bytes         Power of:

 Kilo  (K)  Thousand       3
 Mega  (M)  Million        6
 Giga  (G)  Billion        9
 Tera  (T)  Trillion      12

 Bytes

 Peta  (P)  Quadrillion   15
 Exa   (E)  Quintillion   18
 Zetta (Z)  Sextillion    21
 Yotta (Y)  Septillion    24
 Bronto     Octillion     27
 Geop       Nonillion     30

 Storage Capacity Measured in:

 CPU word size        bits

 Disk/SSD/USB drive   bytes
 Memory (RAM)         bytes


 ****************************************  T I M E  ***************************************Fractions of a second    10 to theSecond                  Power of:

 Millisecond (ms) Thousandth     -3
 Microsecond (µs) Millionth      -6
 Nanosecond  (ns) Billionth      -9
 Picosecond  (ps) Trillionth    -12
 Femtosecond (fs) Quadrillionth -15
 Attosecond  (as) Quintillionth -18
 Zeptosecond (zs) Sextillionth  -21
 Yoctosecond (ys) Septillionth  -24


 Transmit/Transfer Measured in:

 Parallel bus/channel    bytes/sec
 Disk/solid state drive  bytes/sec
 Memory (RAM)            bytes/sec
 PCI Express bus         bytes/sec

 Cellular data plan      bytes

 USB                     bits/sec
 Network/communications  bits/sec

 Disk access time        ms
 SSD access time         µs
 RAM access time         ns
 Machine cycle           µs, ns
 Instruction execution   µs, ns
 Transistor switching    ns, ps, fs


 CPU Speed - Clock Cycles Per Second
 (1 cycle/sec = 1 Hertz)  See  Hertz.

 kilohertz (kHz) thousand
 megahertz (MHz) million
 gigahertz (GHz) billion

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