Numbers Everyone Should Know

Some of you have seen me build simple models to do a reality-check on architecture (see here, for example). Here are some metrics from a great presentation by Jeff Dean, a Google fellow.

Numbers Everyone Should Know

Some of you have seen me build simple models to do a reality-check on architecture (see here, for example). Here are some metrics from a great presentation by Jeff Dean, a Google fellow.

Numbers Everyone Should Know

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
Send 2K bytes over 1 Gbps network	20,000 ns
Read 1 MB sequentially from memory	250,000 ns
Round trip within same datacenter	500,000 ns
Disk seek	10,000,000 ns
Read 1 MB sequentially from disk	20,000,000 ns
Send packet CA->Netherlands->CA	150,000,000 ns