

Flash and the five-minute rule (J.Gray, SSD, costs) - ableal
http://www.theregister.co.uk/2010/05/19/flash_5_minute_rule/

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ableal
Snippet:

 _The rule is worked out like this: you calculate the break-even relative
interval (RI), and if it's less than five minutes you cache the data. The
formula is:

RI = (Data pages per MB / IOPS per disk) x (price of disk / price per MB of
RAM)_

Went looking for illustrative charts, but only found some tables in a similar
2008 piece at <http://queue.acm.org/detail.cfm?id=1413264> \- The Five-Minute
Rule 20 Years Later: and How Flash Memory Changes the Rules, by Goetz Graefe

Some charts in the 1987 SIGMOD paper,
[http://books.google.com/books?id=7a48qSMuVcUC&pg=PA224](http://books.google.com/books?id=7a48qSMuVcUC&pg=PA224)
\- The Five-Minute Rule Ten Years Later, and Other Computer Storage Rules of
Thumb, by Jim Gray, Goetz Graefe. With color:
ftp://ftp.research.microsoft.com/pub/tr/tr-97-33.pdf

