PaaS Under The Hood, Episode 6: How to Optimize the Memory Usage of Your Apps (blog.dotcloud.com) 11 points by jpetazzo 13y ago ↗ HN
[–] hoop 13y ago ↗ For those interested or surprised by the quote "There is a huge performance difference between memory and disk. RAM is typically 100x to 1000x faster than disk" you may also enjoy Jeff Dean's (of Google) "Numbers Everyone Should Know."L1 cache reference..............................0.5nsBranch mispredict.................................5nsL2 cache reference................................7nsMutex lock/unlock................................25nsMemory reference................................100nsCompress 1K bytes with Zippy..................3,000nsSend 2k bytes over 1Gbps network.............20,000nsRead 1MB sequentially from memory...........250,000nsRound trip within datacenter................500,000nsDisk seek................................10,000,000nsRead 1MB sequentially from disk..........20,000,000nsSend packet CA->Netherlands->CA.........150,000,000nshttp://www.regexprn.com/2009/12/numbers-everyone-should-know...
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[ 3.9 ms ] story [ 9.5 ms ] threadL1 cache reference..............................0.5ns
Branch mispredict.................................5ns
L2 cache reference................................7ns
Mutex lock/unlock................................25ns
Memory reference................................100ns
Compress 1K bytes with Zippy..................3,000ns
Send 2k bytes over 1Gbps network.............20,000ns
Read 1MB sequentially from memory...........250,000ns
Round trip within datacenter................500,000ns
Disk seek................................10,000,000ns
Read 1MB sequentially from disk..........20,000,000ns
Send packet CA->Netherlands->CA.........150,000,000ns
http://www.regexprn.com/2009/12/numbers-everyone-should-know...