for a long time i used a variation of this as an interview question for performance analysis positions at google. instead of focusing on I/O costs i was focusi

for a long time i used a variation of this as an interview question for performance analysis positions at google. instead of focusing on I/O costs i was focusing on cache miss costs, but it's pretty much the same observation at a different scale. it's always seemed like an excellent educational example of the difference between theoretical and practical concepts in computer engineering, such as big-O and turing machine vs. practical problem sizes and hierarchical storage/cache capacities/costs.