Memory

Speed Quantity Cost Type Caches
VERY FAST!
   < 1ns
Few
(1-20)
$$$ Registers
(on CPU chip)
Cache (on chip):
data from memory
instructions from mem.
Fast.
   < < 1 us
Megabytes $$ Memory
(RAM)
Disk Cache (in memory):
previously read
from disk
Slow.
   10 ms
Gigabytes $ Storage
(Hard Disk)
Browser Cache (on disk):
pages from internet
Slower.
   seconds
Unlimited ¢ Removable Storage
Floppy Disk
Sequential Tape
(floppy-disk cache)
VERY SLOW!
   seconds
   (or minutes)
Unlimited zero
(no additional cost)
Internet
(cloud)