Latency numbers every programmer should know

latency.txt

L1 cache reference                  0.5 ns
Branch mispredict                   5 ns
L2 cache reference                  7 ns
Mutex lock/unlock                   25 ns
Main memory reference               100 ns             
Compress 1K bytes with Zippy        3,000 ns           3 µs
Send 2K bytes over 1 Gbps network   20,000 ns         20 µs
Read 1 MB sequentially from memory  250,000 ns       250 µs
Round trip within same datacenter   500,000 ns       0.5 ms
Disk seek                           10,000,000 ns     10 ms
Read 1 MB sequentially from disk    20,000,000 ns     20 ms
Send packet CA->Netherlands->CA     150,000,000 ns   150 ms

By Jeff Dean (http://research.google.com/people/jeff/):

latency_humanized.markdown

Lets multiply all these durations by a billion:

Magnitudes:

Minute:

L1 cache reference                  0.5 s         One Heart Beat (0.5 s)
Branch mispredict                   5 s           Yawn
L2 cache reference                  7 s           Long Yawn
Mutex lock/unlock                   25 s          ?

Hour:

Main memory reference               100 s         Brushing your teeth
Compress 1K bytes with Zippy        50 min        One episode of a TV show (including ad breaks)

Day:

Send 2K bytes over 1 Gbps network   5.5 hr        Flight duration from Hawaii to Utah

Week

Read 1 MB sequentially from memory  2.9 days      A long weekend.
Round trip within same datacenter   5.8 days      A medium vacation

Year

Disk seek                           16.5 weeks    ?
Read 1 MB sequentially from disk    7.8 months    ?

Decade

Send packet CA->Netherlands->CA     4.8 years     ?