| 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 | Limited only by physical size. | ¢ | Removable Storage
Floppy Disk Sequential Tape | ||
| (floppy-disk cache) | |||||
| VERY SLOW! seconds (or minutes) | Unlimited | zero (no additional cost) | Internet (cloud) | ||