Clojure High Performance Programming - Second Edition

The latency numbers that every programmer should know

Hardware and software have progressed over the years. Latencies for various operations put things in perspective. The latency numbers for the year 2015, reproduced with the permission of Aurojit Panda and Colin Scott of Berkeley University (http://www.eecs.berkeley.edu/~rcs/research/interactive_latency.html). Latency numbers that every programmer should know are as shown in the following table:

Operation	Time taken as of 2015
L1 cache reference	1ns (nano second)
Branch mispredict	3 ns
L2 cache reference	4 ns
Mutex lock/unlock	17 ns
Compress 1KB with Zippy (Zippy/Snappy: http://code.google.com/p/snappy/)	2μs (1000 ns = 1μs: micro second)
Send 2000 bytes over the commodity network ...