O'Reilly logo

Deep Learning by Adam Gibson, Josh Patterson

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Appendix C. Numbers Everyone Should Know

Table C-1 lists the numbers everyone should know, also known as “Jeff Dean’s 12 Numbers.”

Table C-1. Jeff Dean’s 12 numbers
Computer architecture operation Duration (in nanoseconds)
L1 cache reference 0.5
Branch mispredict 5
L2 cache reference 7
Mutex lock/unlock 100
Main memory reference 100
Compress 1 KB with Zippy 10,000
Send 2 KB over 1 Gbps network 20,000
Read 1 MB sequentially from memory 250,000
Roundtrip within same datacenter 500,000
Disk seek 10,000,000
Read 1 MB sequentially from network 10,000,000
Read 1 MB sequentially from disk 30,000,000
Send packet CA->Netherlands->CA 150,000,000

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required